RFC2350 - Expectations for Computer Security Incident Response

Network Working Group N. Brownlee
Request for Comments: 2350 The University of AUCkland
BCP: 21 E. Guttman
Category: Best Current Practice Sun Microsystems
June 1998
EXPectations for Computer Security Incident Response
Status of this Memo
This document specifies an Internet Best Current Practices for the
Internet Community, and requests discussion and suggestions for
improvements. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
The purpose of this document is to express the general Internet
community"s expectations of Computer Security Incident Response Teams
(CSIRTs). It is not possible to define a set of requirements that
would be appropriate for all teams, but it is possible and helpful to
list and describe the general set of topics and issues which are of
concern and interest to constituent communities.
CSIRT constituents have a legitimate need and right to fully
understand the policies and procedures of "their" Computer Security
Incident Response Team. One way to support this understanding is to
supply detailed information which users may consider, in the form of
a formal template completed by the CSIRT. An outline of such a
template and a filled in example are provided.
Table of Contents
1 Introduction ....................................................2
2 Scope............................................................4
2.1 Publishing CSIRT Policies and Procedures ....................4
2.2 Relationships between different CSIRTs ......................5
2.3 Establishing Secure Communications ..........................6
3 Information, Policies and Procedures.............................7
3.1 OBTaining the Document.......................................8
3.2 Contact Information .........................................9
3.3 Charter ....................................................10
3.3.1 Mission Statement.....................................10
3.3.2 Constituency..........................................10
3.3.3 Sponsoring Organization / Affiliation.................11
3.3.4 Authority.............................................11
3.4 Policies ...................................................11
3.4.1 Types of Incidents and Level of Support...............11
3.4.2 Co-operation, Interaction and Disclosure of
Information...........................................12
3.4.3 Communication and Authentication......................14
3.5 Services ...................................................15
3.5.1 Incident Response ....................................15
3.5.1.1 Incident Triage ..............................15
3.5.1.2 Incident Coordination ........................15
3.5.1.3 Incident Resolution...........................16
3.5.2 Proactive Activities .................................16
3.6 Incident Reporting Forms ...................................16
3.7 Disclaimers ................................................17
Appendix A: Glossary of Terms ....................................18
Appendix B: Related Material .....................................20
Appendix C: Known Computer Security Incident Response Teams ......21
Appendix D: Outline for CSIRT Template ...........................22
Appendix E: Example - "filled-in" Template for a CSIRT ...........23
4 Acknowlegements ................................................36
5 References .....................................................36
6 Security Considerations ........................................36
7 Authors" Addresses .............................................37
8 Full Copyright Statement .......................................38
1 Introduction
The GRIP Working Group was formed to create a document that describes
the community"s expectations of computer security incident response
teams (CSIRTs). Although the need for such a document originated in
the general Internet community, the expectations expressed should
also closely match those of more restricted communities.
In the past there have been misunderstandings regarding what to
expect from CSIRTs. The goal of this document is to provide a
framework for presenting the important subjects (related to incident
response) that are of concern to the community.
Before continuing, it is important to clearly understand what is
meant by the term "Computer Security Incident Response Team." For
the purposes of this document, a CSIRT is a team that performs,
coordinates, and supports the response to security incidents that
involve sites within a defined constituency (see Appendix A for a
more complete definition). Any group calling itself a CSIRT for a
specific constituency must therefore react to reported security
incidents, and to threats to "their" constituency in ways which the
specific community agrees to be in its general interest.
Since it is vital that each member of a constituent community be able
to understand what is reasonable to expect of their team, a CSIRT
should make it clear who belongs to their constituency and define the
services the team offers to the community. Additionally, each CSIRT
should publish its policies and operating procedures. Similarly,
these same constituents need to know what is expected of them in
order for them to receive the services of their team. This requires
that the team also publish how and where to report incidents.
This document details a template which will be used by CSIRTs to
communicate this information to their constituents. The constituents
should certainly expect a CSIRT to provide the services they describe
in the completed template.
It must be emphasized that without active participation from users,
the effectiveness of the CSIRT"s services can be greatly diminished.
This is particularly the case with reporting. At a minimum, users
need to know that they should report security incidents, and know how
and to where they should report them.
Many computer security incidents originate outside local community
boundaries and affect inside sites, others originate inside the local
community and affect hosts or users on the outside. Often,
therefore, the handling of security incidents will involve multiple
sites and potentially multiple CSIRTs. Resolving these incidents
will require cooperation between individual sites and CSIRTs, and
between CSIRTs.
Constituent communities need to know exactly how their CSIRT will be
working with other CSIRTs and organizations outside their
constituency, and what information will be shared.
The rest of this document describes the set of topics and issues that
CSIRTs need to elaborate for their constituents. However, there is no
attempt to specify the "correct" answer to any one topic area.
Rather, each topic is discussed in terms of what that topic means.
Chapter two provides an overview of three major areas: the
publishing of information by a response team, the definition of the
response team"s relationship to other response teams, and the need
for secure communications. Chapter three describes in detail all the
types of information that the community needs to know about their
response team.
For ease of use by the community, these topics are condensed into an
outline template found in Appendix D. This template can be used by
constituents to elicit information from their CSIRT.
It is the working group"s sincere hope that through clarification of
the topics in this document, understanding between the community and
its CSIRTs will be increased.
2 Scope
The interactions between an incident response team and its
constituent community response team require first that the community
understand the policies and procedures of the response team. Second,
since many response teams collaborate to handle incidents, the
community must also understand the relationship between their
response team and other teams. Finally, many interactions will take
advantage of existing public infrastructures, so the community needs
to know how those communications will be protected. Each of these
subjects will be described in more detail in the following three
sections.
2.1 Publishing CSIRT Policies and Procedures
Each user who has Access to a Computer Security Incident Response
Team should know as much as possible about the services of and
interactions with this team long before he or she actually needs
them.
A clear statement of the policies and procedures of a CSIRT helps the
constituent understand how best to report incidents and what support
to expect afterwards. Will the CSIRT assist in resolving the
incident? Will it provide help in avoiding incidents in the future?
Clear expectations, particularly of the limitations of the services
provided by a CSIRT, will make interaction with it more efficient and
effective.
There are different kinds of response teams: some have very broad
constituencies (e.g., CERT Coordination Center and the Internet),
others have more bounded constituencies (e.g., DFN-CERT, CIAC), and
still others have very restricted constituencies (e.g., commercial
response teams, corporate response teams). Regardless of the type of
response team, the constituency supported by it must be knowledgeable
about the team"s policies and procedures. Therefore, it is mandatory
that response teams publish such information to their constituency.
A CSIRT should communicate all necessary information about its
policies and services in a form suitable to the needs of its
constituency. It is important to understand that not all policies
and procedures need be publicly available. For example, it is not
necessary to understand the internal operation of a team in order to
interact with it, as when reporting an incident or receiving guidance
on how to analyze or secure one"s systems.
In the past, some teams supplied a kind of Operational Framework,
others provided a Frequently Asked Questions list (FAQ), while still
others wrote papers for distribution at user conferences or sent
newsletters.
We recommend that each CSIRT publish its guidelines and procedures on
its own information server (e.g. a World Wide Web server). This
would allow constituents to easily access it, though the problem
remains of how a constituent can find his or her team; people within
the constituency have to discover that there is a CSIRT "at their
disposal."
It is foreseen that completed CSIRT templates will soon become
searchable by modern search engines, which will aid in distributing
information about the existence of CSIRTs and basic information
required to approach them.
It would be very useful to have a central repository containing all
the completed CSIRT templates. No such repository exists at the time
of writing, though this might change in the future.
Regardless of the source from which the information is retrieved, the
user of the template must check its authenticity. It is highly
recommended that such vital documents be protected by digital
signatures. These will allow the user to verify that the template
was indeed published by the CSIRT and that it has not been tampered
with. This document assumes the reader is familiar with the proper
use of digital signatures to determine whether a document is
authentic.
2.2 Relationships between different CSIRTs
In some cases a CSIRT may be able to operate effectively on its own
and in close cooperation with its constituency. But with today"s
international networks it is much more likely that most of the
incidents handled by a CSIRT will involve parties external to its
constituency. Therefore the team will need to interact with other
CSIRTs and sites outside its constituency.
The constituent community should understand the nature and extent of
this collaboration, as very sensitive information about individual
constituents may be disclosed in the process.
Inter-CSIRT interactions could include aSKINg other teams for advice,
disseminating knowledge of problems, and working cooperatively to
resolve a security incident affecting one or more of the CSIRTs"
constituencies.
In establishing relationships to support such interactions, CSIRTs
must decide what kinds of agreements can exist between them so as to
share yet safeguard information, whether this relationship can be
disclosed, and if so to whom.
Note that there is a difference between a peering agreement, where
the CSIRTs involved agree to work together and share information, and
simple co-operation, where a CSIRT (or any other organization) simply
contacts another CSIRT and asks for help or advice.
Although the establishment of such relationships is very important
and affects the ability of a CSIRT to support its constituency, it is
up to the teams involved to decide about the details. It is beyond
the scope of this document to make recommendations for this process.
However, the same set of information used to set expectations for a
user community regarding sharing of information will help other
parties to understand the objectives and services of a specific
CSIRT, supporting a first contact.
2.3 Establishing Secure Communications
Once one party has decided to share information with another party,
or two parties have agreed to share information or work together - as
required for the coordination of computer security incident response
- all parties involved need secure communications channels. (In this
context, "secure" refers to the protected transmission of information
shared between different parties, and not to the appropriate use of
the information by the parties.)
The goals of secure communication are:
- Confidentiality:
Can somebody else access the content of the communication?
- Integrity:
Can somebody else manipulate the content of the communication?
- Authenticity:
Am I communicating with the "right" person?
It is very easy to send forged e-mail, and not hard to establish a
(false) identity by telephone. Cryptographic techniques, for
example Pretty Good Privacy (PGP) or Privacy Enhanced Mail (PEM) can
provide effective ways of securing e-mail. With the correct
equipment it is also possible to secure telephone communication. But
before using such mechanisms, both parties need the "right"
infrastructure, which is to say preparation in advance. The most
important preparation is ensuring the authenticity of the
cryptographic keys used in secure communication:
- Public keys (for techniques like PGP and PEM):
Because they are accessible through the Internet, public keys must
be authenticated before use. While PGP relies on a "Web of Trust"
(where users sign the keys of other users), PEM relies on a
hierarchy (where certification authorities sign the keys of users).
- Secret keys (for techniques like DES and PGP/conventional
encryption): Because these must be known to both sender and
receiver, secret keys must be exchanged before the communication
via a secure channel.
Communication is critical to all ASPects of incident response. A
team can best support the use of the above-mentioned techniques by
gathering all relevant information, in a consistent way. Specific
requirements (such as calling a specific number to check the
authenticity of keys) should be clear from the start. CSIRT
templates provide a standardized vehicle for delivering this
information.
It is beyond the scope of this document to address the technical and
administrative problems of secure communications. The point is that
response teams must support and use a method to secure the
communications between themselves and their constituents (or other
response teams). Whatever the mechanism is, the level of protection
it provides must be acceptable to the constituent community.
3 Information, Policies and Procedures
In chapter 2 it was mentioned that the policies and procedures of a
response team need to be published to their constituent community.
In this chapter we will list all the types of information that the
community needs to receive from its response team. How this
information is communicated to a community will differ from team to
team, as will the specific information content. The intent here is
to clearly describe the various kinds of information that a
constituent community expects from its response team.
To make it easier to understand the issues and topics relevant to the
interaction of constituents with "their" CSIRT, we suggest that a
CSIRT publish all information, policies, and procedures addressing
its constituency as a document, following the template given in
Appendix D. The template structure arranges items, making it easy to
supply specific information; in Appendix E we provide an example of a
filled-out template for the fictitious XYZ University. While no
recommendations are made as to what a CSIRT should adopt for its
policy or procedures, different possibilities are outlined to give
some examples. The most important thing is that a CSIRT have a
policy and that those who interact with the CSIRT be able to obtain
and understand it.
As always, not every aspect for every environment and/or team can be
covered. This outline should be seen as a suggestion. Each team
should feel free to include whatever they think is necessary to
support its constituency.
3.1 Obtaining the Document
Details of a CSIRT change with time, so the completed template must
indicate when it was last changed. Additionally, information should
be provided concerning how to find out about future updates. Without
this, it is inevitable that misunderstandings and misconceptions will
arise over time; outdated documents can do more harm than good.
- Date of last update This should be sufficient to allow
anyone interested to evaluate the
currency of the template.
- Distribution list Mailing lists are a convenient
mechanism to distribute up-to-date
information to a large number of
users. A team can decide to use its
own or an already existing list to
notify users whenever the document
changes. The list might normally be
groups the CSIRT has frequent
interactions with.
Digital signatures should be used
for update messages sent by a CSIRT.
- Location of the document The location where a current version
of the document is accessible through
a team"s online information services.
Constituents can then easily learn
more about the team and check for
recent updates. This online version
should also be accompanied by a
digital signature.
3.2 Contact Information
Full details of how to contact the CSIRT should be listed here,
although this might be very different for different teams; for
example, some might choose not to publicize the names of their team
members. No further clarification is given when the meaning of the
item can be assumed.
- Name of the CSIRT
- Mailing Address
- Time zone This is useful for coordinating
incidents which cross time zones.
- Telephone number
- Facsimile number
- Other telecommunication Some teams might provide secure
voice communication (e.g. STU III).
- Electronic mail address
- Public keys and encryption The use of specific techniques
depends on the ability of the
communication partners to have
access to programs, keys and so on.
Relevant information should be
given to enable users to determine
if and how they can make use of
encrypted communication while
interacting with the CSIRT.
- Team members
- Operating Hours The operating hours and holiday
schedule should be provided here.
Is there a 24 hour hotline?
- Additional Contact Info Is there any specific customer
contact info?
More detailed contact information can be provided. This might
include different contacts for different services, or might be a list
of online information services. If specific procedures for access to
some services exist (for example addresses for mailing list
requests), these should be explained here.
3.3 Charter
Every CSIRT must have a charter which specifies what it is to do, and
the authority under which it will do it. The charter should include
at least the following items:
- Mission statement
- Constituency
- Sponsorship / affiliation
- Authority
3.3.1 Mission Statement
The mission statement should focus on the team"s core activities,
already stated in the definition of a CSIRT. In order to be
considered a Computer Security Incident Response Team, the team must
support the reporting of incidents and support its constituency by
dealing with incidents.
The goals and purposes of a team are especially important, and
require clear, unambiguous definition.
3.3.2 Constituency
A CSIRT"s constituency can be determined in any of several ways. For
example it could be a company"s employees or its paid subscribers, or
it could be defined in terms of a technological focus, such as the
users of a particular operating system.
The definition of the constituency should create a perimeter around
the group to whom the team will provide service. The policy section
of the document (see below) should explain how requests from outside
this perimeter will be handled.
If a CSIRT decides not to disclose its constituency, it should
explain the reasoning behind this decision. For example, for-fee
CSIRTs will not list their clients but will declare that they provide
a service to a large group of customers that are kept confidential
because of the clients" contracts.
Constituencies might overlap, as when an ISP provides a CSIRT which
delivers services to customer sites that also have CSIRTs. The
Authority section of the CSIRT"s description (see below) should make
such relationships clear.
3.3.3 Sponsoring Organization / Affiliation
The sponsoring organization, which authorizes the actions of the
CSIRT, should be given next. Knowing this will help the users to
understand the background and set-up of the CSIRT, and it is vital
information for building trust between a constituent and a CSIRT.
3.3.4 Authority
This section will vary greatly from one CSIRT to another, based on
the relationship between the team and its constituency. While an
organizational CSIRT will be given its authority by the management of
the organization, a community CSIRT will be supported and chosen by
the community, usually in a advisory role.
A CSIRT may or may not have the authority to intervene in the
operation of all of the systems within its perimeter. It should
identify the scope of its control as distinct from the perimeter of
its constituency. If other CSIRTs operate hierarchically within its
perimeter, this should be mentioned here, and the related CSIRTs
identified.
Disclosure of a team"s authority may expose it to claims of
liability. Every team should seek legal advice on these matters.
(See section 3.7 for more on liability.)
3.4 Policies
It is critical that Incident Response Teams define their policies.
The following sections discuss communication of these policies to the
constituent community.
3.4.1 Types of Incidents and Level of Support
The types of incident which the team is able to address, and the
level of support which the team will offer when responding to each
type of incident, should be summarized here in list form. The
Services section (see below) provides the opportunity to give more
detailed descriptions, and to address non-incident-related topics.
The level of support may change depending on factors such as the
team"s workload and the completeness of the information available.
Such factors should be outlined and their impact should be explained.
As a list of known types of incidents will be incomplete with regard
to possible or future incidents, a CSIRT should also give some
background on the "default" support for incident types not otherwise
mentioned.
The team should state whether it will act on information it receives
about vulnerabilities which create opportunities for future
incidents. A commitment to act on such information on behalf of its
constituency is regarded as an optional proactive service policy
rather than a core service requirement for a CSIRT.
3.4.2 Co-operation, Interaction and Disclosure of Information
This section should make explicit which related groups the CSIRT
routinely interacts with. Such interactions are not necessarily
related to the computer security incident response provided, but are
used to facilitate better cooperation on technical topics or
services. By no means need details about cooperation agreements be
given out; the main objective of this section is to give the
constituency a basic understanding of what kind of interactions are
established and what their purpose is.
Cooperation between CSIRTs can be facilitated by the use of unique
ticket number assignment combined with explicit handoff procedures.
This reduces the chance of misunderstandings, duplications of effort,
assists in incident tracking and prevents "loops" in communication.
The reporting and disclosure policy should make clear who will be the
recipients of a CSIRT"s report in each circumstance. It should also
note whether the team will expect to operate through another CSIRT or
directly with a member of another constituency over matters
specifically concerning that member.
Related groups a CSIRT will interact with are listed below:
Incident Response Teams:
A CSIRT will often need to interact with other CSIRTs. For
example a CSIRT within a large company may need to report
incidents to a national CSIRT, and a national CSIRT may need to
report incidents to national CSIRTs in other countries to deal
with all sites involved in a large-scale attack.
Collaboration between CSIRTs may lead to disclosure of
information. The following are examples of such disclosure, but
are not intended to be an exhaustive list:
- Reporting incidents within the constituency to other teams.
If this is done, site-related information may become public
knowledge, accessible to everyone, in particular the press.
- Handling incidents occurring within the constituency, but
reported from outside it (which implies that some information
has already been disclosed off-site).
- Reporting observations from within the constituency indicating
suspected or confirmed incidents outside it.
- Acting on reports of incidents from outside the constituency.
- Passing information about vulnerabilities to vendors, to
partner CSIRTs or directly to affected sites lying within or
outside the constituency.
- Feedback to parties reporting incidents or vulnerabilities.
- The provision of contact information relating to members of
the constituency, members of other constituencies, other
CSIRTs, or law-enforcement agencies.
Vendors:
Some vendors have their own CSIRTs, but some vendors may not. In
such cases a CSIRT will need to work directly with a vendor to
suggest improvements or modifications, to analyze the technical
problem or to test provided solutions. Vendors play a special
role in handling an incident if their products" vulnerabilities
are involved in the incident.
Law-enforcement agencies:
These include the police and other investigative agencies. CSIRTs
and users of the template should be sensitive to local laws and
regulations, which may vary considerably in different countries.
A CSIRT might advise on technical details of attacks or seek
advice on the legal implications of an incident. Local laws and
regulations may include specific reporting and confidentiality
requirements.
Press:
A CSIRT may be approached by the press for information and comment
from time to time.
An explicit policy concerning disclosure to the press can be
helpful, particularly in clarifying the expectations of a CSIRT"s
constituency. The press policy will have to clarify the same
topics as above more specifically, as the constituency will
usually be very sensitive to press contacts.
Other:
This might include research activities or the relation to the
sponsoring organization.
The default status of any and all security-related information which
a team receives will usually be "confidential," but rigid adherence
to this makes the team to appear to be an informational "black hole,"
which may reduce the likelihood of the team"s obtaining cooperation
from clients and from other organizations. The CSIRT"s template
should define what information it will report or disclose, to whom,
and when.
Different teams are likely to be subject to different legal
restraints requiring or limiting disclosure, especially if they work
in different jurisdictions. In addition, they may have reporting
requirements imposed by their sponsoring organization. Each team"s
template should specify any such constraints, both to clarify users"
expectations and to inform other teams.
Conflicts of interest, particularly in commercial matters, may also
restrain disclosure by a team; this document does not recommend on
how such conflicts should be addressed.
A team will normally collect statistics. If statistical information
is distributed, the template"s reporting and disclosure policy should
say so, and should describe how to obtain such statistics.
3.4.3 Communication and Authentication
You must have a policy which describes methods of secure and
verifiable communication that you will use. This is necessary for
communication between CSIRTs and between a CSIRT and its
constituents. The template should include public keys or pointers to
them, including key fingerprints, together with guidelines on how to
use this information to check authenticity and how to deal with
corrupted information (for example where to report this fact).
At the moment it is recommended that as a minimum every CSIRT have
(if possible), a PGP key available. A team may also make other
mechanisms available (for example PEM, MOSS, S/MIME), according to
its needs and the needs of its constituents. Note however, that
CSIRTs and users should be sensitive to local laws and regulations.
Some countries do not allow strong encryption, or enforce specific
policies on the use of encryption technology. In addition to
encrypting sensitive information whenever possible, correspondence
should include digital signatures. (Please note that in most
countries, the protection of authenticity by using digital signatures
is not affected by existing encryption regulations.)
For communication via telephone or facsimile a CSIRT may keep secret
authentication data for parties with whom they may deal, such as an
agreed passWord or phrase. Obviously, such secret keys must not be
published, though their existence may be.
3.5 Services
Services provided by a CSIRT can be roughly divided into two
categories: real-time activities directly related to the main task of
incident response, and non-real-time proactive activities, supportive
of the incident response task. The second category and part of the
first category consist of services which are optional in the sense
that not all CSIRTs will offer them.
3.5.1 Incident Response
Incident response usually includes assessing incoming reports about
incidents ("Incident Triage") and following up on these with other
CSIRTs, ISPs and sites ("Incident Coordination"). A third range of
services, helping a local site to recover from an incident ("Incident
Resolution"), is comprised of typically optional services, which not
all CSIRTs will offer.
3.5.1.1 Incident Triage
Incident triage usually includes:
- Report assessment Interpretion of incoming incident
reports, prioritizing them, and
relating them to ongoing incidents
and trends.
- Verification Help in determining whether an
incident has really occurred, and
its scope.
3.5.1.2 Incident Coordination
Incident Coordination normally includes:
- Information categorization Categorization of the incident related
information (logfiles, contact
information, etc.) with respect to
the information disclosure policy.
- Coordination Notification of other involved
parties on a need-to-know basis, as
per the information disclosure
policy.
3.5.1.3 Incident Resolution
Usually additional or optional, incident resolution services
include:
- Technical Assistance This may include analysis of
compromised systems.
- Eradication Elimination of the cause of a
security incident (the vulnerability
exploited), and its effects (for
example, continuing access to the
system by an intruder).
- Recovery Aid in restoring affected systems
and services to their status before
the security incident.
3.5.2. Proactive Activities
Usually additional or optional, proactive services might include:
- Information provision This might include an archive of
known vulnerabilities, patches or
resolutions of past problems, or
advisory mailing lists.
- Security Tools This may include tools for auditing
a Site"s security.
- Education and training
- Product evaluation
- Site security auditing and consulting
3.6 Incident Reporting Forms
The use of reporting forms makes it simpler for both users and teams
to deal with incidents. The constituent can prepare answers to
various important questions before he or she actually contacts the
team, and can therefore come well prepared. The team gets all the
necessary information at once with the first report and can proceed
efficiently.
Depending on the objectives and services of a particular CSIRT,
multiple forms may be used, for example a reporting form for a new
vulnerability may be very different from the form used for reporting
incidents.
It is most efficient to provide forms through the online information
services of the team. The exact pointers to them should be given in
the CSIRT description document, together with statements about
appropriate use, and guidelines for when and how to use the forms. If
separate e-mail addresses are supported for form-based reporting,
they should be listed here again.
One example of such a form is the Incident Reporting Form provided by
the CERT Coordination Center:
- FTP://info.cert.org/incident_reporting_form
3.7 Disclaimers
Although the CSIRT description document does not constitute a
contract, liability may conceivably result from its descriptions of
services and purposes. The inclusion of a disclaimer at the end of
the template is therefore recommended and should warn the user about
possible limitations.
In situations where the original version of a document must be
translated into another language, the translation should carry a
disclaimer and a pointer to the original. For example:
Although we tried to carefully translate the original document
from German into English, we can not be certain that both
documents express the same thoughts in the same level of detail
and correctness. In all cases, where there is a difference
between both versions, the German version will prevail.
The use of and protection by disclaimers is affected by local laws
and regulations, of which each CSIRT should be aware. If in doubt the
CSIRT should check the disclaimer with a lawyer.
Appendix A: Glossary of Terms
This glossary defines terms used in describing security incidents and
Computer Security Incident Response Teams. Only a limited list is
included. For more definitions please refer to other sources, for
example to the Internet User"s Glossary [RFC1983].
Constituency:
Implicit in the purpose of a Computer Security Incident Response
Team is the existence of a constituency. This is the group of
users, sites, networks or organizations served by the team. The
team must be recognized by its constituency in order to be
effective.
Security Incident:
For the purpose of this document, this term is a synonym of
Computer Security Incident: any adverse event which compromises
some aspect of computer or network security.
The definition of an incident may vary between organizations, but
at least the following categories are generally applicable:
- Loss of confidentiality of information.
- Compromise of integrity of information.
- Denial of service.
- Misuse of service, systems or information.
- Damage to systems.
These are very general categories. For instance the replacement
of a system utility program by a Trojan Horse is an example of "
compromise of integrity," and a successful password attack is an
example of "loss of confidentiality." Attacks, even if they
failed because of proper protection, can be regarded as Incidents.
Within the definition of an incident the word "compromised" is
used. Sometimes an administrator may only "suspect" an incident.
During the response it must be established whether or not an
incident has really occurred.
Computer Security Incident Response Team:
Based on two of the definitions given above, a CSIRT is a team
that coordinates and supports the response to security incidents
that involve sites within a defined constituency.
In order to be considered a CSIRT, a team must:
- Provide a (secure) channel for receiving reports about
suspected incidents.
- Provide assistance to members of its constituency in
handling these incidents.
- Disseminate incident-related information to its
constituency and to other involved parties.
Note that we are not referring here to police or other law
enforcement bodies which may investigate computer-related crime.
CSIRT members, indeed, need not have any powers beyond those of
ordinary citizens.
Vendor:
A "vendor" is any entity that produces networking or computing
technology, and is responsible for the technical content of that
technology. Examples of "technology" include hardware (desktop
computers, routers, switches, etc.), and software (operating
systems, mail forwarding systems, etc.).
Note that the supplier of a technology is not necessarily the "
vendor" of that technology. As an example, an Internet Service
Provider (ISP) might supply routers to each of its customers, but
the "vendor" is the manufacturer, since the manufacturer, rather
than the ISP, is the entity responsible for the technical content
of the router.
Vulnerability:
A "vulnerability" is a characteristic of a piece of technology
which can be exploited to perpetrate a security incident. For
example, if a program unintentionally allowed ordinary users to
execute arbitrary operating system commands in privileged mode,
this "feature" would be a vulnerability.
Appendix B: Related Material
Important issues in responding to security incidents on a site level
are contained in [RFC2196], the Site Security Handbook, produced by
the Site Security Handbook Working Group (SSH). This document will
be updated by the SSH working group and will give recommendations for
local policies and procedures, mainly related to the avoidance of
security incidents.
Other documents of interest for the discussion of CSIRTs and their
tasks are available by anonymous FTP. A collection can be found on:
- ftp://ftp.cert.dfn.de/pub/docs/csir/
Please refer to file 01-README for further information about
the content of this Directory.
Some especially interesting documents in relation to this document
are as follows:
- ftp://ftp.nic.surfnet.nl/surfnet/net-security/cert-nl/docs/
reports/R-92-01
This report contains the Operational Framework of CERT-NL, the
CSIRT of SURFnet (network provider in the Netherlands).
- For readers interested in the operation of FIRST (Forum of
Incident Response and Security Teams) more information is
collected in Appendix C.
- http://hightop.nrl.navy.mil/news/incident.Html
This document leads to the NRL Incident Response Manual.
- http://www.cert.dfn.de/eng/team/kpk/certbib.html
This document contains an annotated bibliography of available
material, documents and files about the operation of CSIRTs
with links to many of the referenced items.
- ftp://info.cert.org/incident_reporting_form
This Incident Reporting Form is provided by the CERT
Coordination Center to gather incident information and to avoid
additional delays caused by the need to request more detailed
information from the reporting site.
- http://www.cert.org/cert.faqintro.html
A collection of frequently asked questions from the CERT
Coordination Center.
Appendix C: Known Computer Security Incident Response Teams
Today, there are many different CSIRTs but no single source lists
every team. Most of the major and long established teams (the first
CSIRT was founded in 1988) are nowadays members of FIRST, the
worldwide Forum of Incident Response and Security Teams. At the time
of writing, more than 55 teams are members (1 in Australia, 13 in
Europe, all others in North America). Information about FIRST can be
found:
- http://www.first.org/
The current list of members is available also, with the relevant
contact information and some additional information provided by the
particular teams:
- http://www.first.org/team-info/
For CSIRTs which want to become members of this forum (please note
that a team needs a sponsor - a team which is already a full member
of FIRST - to be introduced), the following files contain more
information:
- http://www.first.org/about/op_frame.html
The Operational Framework of FIRST.
- http://www.first.org/docs/newmem.html
Guidelines for teams which want to become members of FIRST.
Many of the European teams, regardless of whether they are members
of FIRST or not, are listed by countries on a page maintained by
the German CSIRT:
- http://www.cert.dfn.de/eng/csir/europe/certs.html
To learn about existing teams suitable to one"s needs it is
often helpful to ask either known teams or an Internet Service
Provider for the "right" contact.
Appendix D: Outline for CSIRT Template
This outline summarizes in point form the issues addressed in this
document, and is the recommended template for a CSIRT description
document. Its structure is designed to facilitate the communication
of a CSIRT"s policies, procedures, and other relevant information to
its constituency and to outside organizations such as other CSIRTs. A
"filled-in" example of this template is given as Appendix E.
1. Document Information
1.1 Date of Last Update
1.2 Distribution List for Notifications
1.3 Locations where this Document May Be Found
2. Contact Information
2.1 Name of the Team
2.2 Address
2.3 Time Zone
2.4 Telephone Number
2.5 Facsimile Number
2.6 Other Telecommunication
2.7 Electronic Mail Address
2.8 Public Keys and Encryption Information
2.9 Team Members
2.10 Other Information
2.11 Points of Customer Contact
3. Charter
3.1 Mission Statement
3.2 Constituency
3.3 Sponsorship and/or Affiliation
3.4 Authority
4. Policies
4.1 Types of Incidents and Level of Support
4.2 Co-operation, Interaction and Disclosure of Information
4.3 Communication and Authentication
5. Services
5.1 Incident Response
5.1.1. Incident Triage
5.1.2. Incident Coordination
5.1.3. Incident Resolution
5.2 Proactive Activities
6. Incident Reporting Forms
7. Disclaimers
Appendix E: Example - "filled-in" Template for a CSIRT
Below is an example of a filled-in template for a fictitious CSIRT
called XYZ-CSIRT. This text is for example purposes only, and does
not constitute endorsement by the working group or the IETF of any
particular set of procedures or policies. While CSIRTs are welcome
to use any or all of this text if they wish, such use is of course
not mandatory, or even appropriate in most cases.
CSIRT Description for XYZ-CERT
-----------------------------
1. About this document
1.1 Date of Last Update
This is version 1.01, published 1997/03/31.
1.2 Distribution List for Notifications
Notifications of updates are submitted to our mailing list
<xyz-cert-info@xyz-univ.ca>. Subscription requests for this
list should be sent to the Majordomo at
<xyz-cert-info-request@xyz-univ.ca>the body of the message
should consist of the word "subscribe". Send the word "help"
instead if you don"t know how to use a Majordomo list manager.
This mailing list is moderated.
1.3 Locations where this Document May Be Found
The current version of this CSIRT description document is
available from the XYZ-CERT WWW site; its URL is
http://www.xyz-univ.ca/xyz-cert/english/CSIRT-descr.txt
Une version francaise de ce document est igalement disponible:
http://www.xyz-univ.ca/xyz-cert/francais/CSIRT-descr.txt
Please make sure you are using the latest version.
1.4 Authenticating this Document
Both the English and French versions of this document have
been signed with the XYZ-CERT"s PGP key. The signatures are
also on our Web site, under:
http://www.xyz-univ.ca/xyz-cert/english/CSIRT-descr.asc
http://www.xyz-univ.ca/xyz-cert/francais/CSIRT-descr.asc
2. Contact Information
2.1 Name of the Team
"XYZ-CERT": the XYZ University Computer Emergency Response
Team.
2.2 Address
XYZ-CERT
XYZ University, Computing Services Department
12345 Rue Principale
UniversityTown, Quebec
Canada H0H 0H0
2.3 Time Zone
Canada/Eastern (GMT-0500, and GMT-0400 from April to October)
2.4 Telephone Number
+1 234 567 7890 (ask for the XYZ-CERT)
2.5 Facsimile Number
+1 234 567 7899 (this is *not* a secure fax)
2.6 Other Telecommunication
None available.
2.7 Electronic Mail Address
<xyz-cert@xyz-univ.ca> This is a mail alias that relays mail
to the human(s) on duty for the XYZ-CERT.
2.8 Public Keys and Other Encryption Information
The XYZ-CERT has a PGP key, whose KeyID is 12345678 and
whose fingerprint is
11 22 33 44 55 66 77 88 88 77 66 55 44 33 22 11.
The key and its signatures can be found at the usual large
public keyservers.
Because PGP is still a relatively new technology at XYZ
University, this key still has relatively few signatures;
efforts are underway to increase the number of links to this
key in the PGP "web of trust". In the meantime, since most
fellow universities in Quebec have at least one staff member
who knows the XYZ-CERT coordinator Zoe Doe, Zoe Doe has
signed the XYZ-CERT key, and will be happy to confirm its
fingerprint and that of her own key to those people who know
her, by telephone or in person.
2.9 Team Members
Zoe Doe of Computing Services is the XYZ-CERT coordinator.
Backup coordinators and other team members, along with their
areas of expertise and contact information, are listed in the
XYZ-CERT web pages, at
http://www.xyz-univ.ca/xyz-cert/teamlist.html
Management, liaison and supervision are provided by Steve Tree,
Assistant Director (Technical Services), Computing Services.
2.10 Other Information
General information about the XYZ-CERT, as well as links to
various recommended security resources, can be found at
http://www.xyz-univ.ca/xyz-cert/index.html
2.11 Points of Customer Contact
The preferred method for contacting the XYZ-CERT is via
e-mail at <xyz-cert@xyz-univ.ca>e-mail sent to this address
will "biff" the responsible human, or be automatically
forwarded to the appropriate backup person, immediately. If
you require urgent assistance, put "urgent" in your subject
line.
If it is not possible (or not advisable for security reasons)
to use e-mail, the XYZ-CERT can be reached by telephone during
regular Office hours. Telephone messages are checked less
often than e-mail.
The XYZ-CERT"s hours of operation are generally restricted to
regular business hours (09:00-17:00 Monday to Friday except
holidays).
If possible, when submitting your report, use the form
mentioned in section 6.
3. Charter
3.1 Mission Statement
The purpose of the XYZ-CERT is, first, to assist members of XYZ
University community in implementing proactive measures to
reduce the risks of computer security incidents, and second, to
assist XYZ community in responding to such incidents when they
occur.
3.2 Constituency
The XYZ-CERT"s constituency is the XYZ University community,
as defined in the context of the "XYZ University Policy on
Computing Facilities". This policy is available at
http://www-compserv.xyz-univ.ca/policies/pcf.html
However, please note that, notwithtanding the above, XYZ-CERT
services will be provided for on-site systems only.
3.3 Sponsorship and/or Affiliation
The XYZ-CERT is sponsored by the ACME Canadian Research
Network. It maintains affiliations with various University
CSIRTs throughout Canada and the USA on an as needed basis.
3.4 Authority
The XYZ-CERT operates under the auspices of, and with authority
delegated by, the Department of Computing Services of XYZ
University. For further information on the mandate and
authority of the Department of Computing Services, please
refer to the XYZ University "Policy on Computing Facilities",
available at
http://www-compserv.xyz-univ.ca/policies/pcf.html
The XYZ-CERT expects to work cooperatively with system
administrators and users at XYZ University, and, insofar as
possible, to avoid authoritarian relationships. However,
should circumstances warrant it, the XYZ-CERT will appeal to
Computing Services to exert its authority, direct or indirect,
as necessary. All members of the XYZ-CERT are members of the
CCSA (Committee of Computer Systems Administrators), and have
all of the powers and responsibilities assigned to Systems
Administrators by the Policy on Computing Facilities, or are
members of University management.
Members of the XYZ University community who wish to appeal the
actions of the XYZ-CERT should contact the Assistant Director
(Technical Services), Computing Services. If this recourse is
not satisfactory, the matter may be referred to the Director
of Computing Services (in the case of perceived
problems with existing policy), or to the XYZ University
Office of Rights and Responsibilities (in the case of perceived
errors in the application of existing policy).
4. Policies
4.1 Types of Incidents and Level of Support
The XYZ-CERT is authorized to address all types of computer
security incidents which occur, or threaten to occur, at
XYZ University.
The level of support given by XYZ-CERT will vary depending on
the type and severity of the incident or issue, the type of
constituent, the size of the user community affected, and the
XYZ-CERT"s resources at the time, though in all cases some
response will be made within one working day. Resources will
be assigned according to the following priorities, listed in
decreasing order:
- Threats to the physical safety of human beings.
- Root or system-level attacks on any Management Information
System, or any part of the backbone network infrastructure.
- Root or system-level attacks on any large public service
machine, either multi-user or dedicated-purpose.
- Compromise of restricted confidential service accounts or
software installations, in particular those used for MIS
applications containing confidential data, or those used
for system administration.
- Denial of service attacks on any of the above three items.
- Any of the above at other sites, originating from XYZ
University.
- Large-scale attacks of any kind, e.g. sniffing attacks,
IRC "social engineering" attacks, password cracking
attacks.
- Threats, harassment, and other criminal offenses
involving individual user accounts.
- Compromise of individual user accounts on multi-user
systems.
- Compromise of desktop systems.
- Forgery and misrepresentation, and other security-related
violations of local rules and regulations, e.g. netnews
and e-mail forgery, unauthorized use of IRC bots.
- Denial of service on individual user accounts, e.g.
mailbombing.
Types of incidents other than those mentioned above will be
prioritized according to their apparent severity and extent.
Note that no direct support will be given to end users; they
are expected to contact their system administrator, network
administrator, or department head for assistance. The XYZ-CERT
will support the latter people.
While the XYZ-CERT understands that there exists great
variation in the level of system administrator expertise at XYZ
University, and while the XYZ-CERT will endeavor to present
information and assistance at a level appropriate to each
person, the XYZ-CERT cannot train system administrators on the
fly, and it cannot perform system maintenance on their behalf.
In most cases, the XYZ-CERT will provide pointers to the
information needed to implement appropriate measures.
The XYZ-CERT is committed to keeping the XYZ University system
administration community informed of potential vulnerabilities,
and where possible, will inform this community of such
vulnerabilities before they are actively exploited.
4.2 Co-operation, Interaction and Disclosure of Information
While there are legal and ethical restrictions on the flow of
information from XYZ-CERT, many of which are also outlined in
the XYZ University Policy on Computing Facilities, and all of
which will be respected, the XYZ-CERT acknowledges its
indebtedness to, and declares its intention to contribute to,
the spirit of cooperation that created the Internet.
Therefore, while appropriate measures will be taken to protect
the identity of members of our constituency and members of
neighbouring sites where necessary, the XYZ-CERT will otherwise
share information freely when this will assist others in
resolving or preventing security incidents.
In the paragraphs below, "affected parties" refers to the
legitimate owners, operators, and users of the relevant
computing facilities. It does not refer to unauthorized
users, including otherwise authorized users making
unauthorized use of a facility; such intruders may have no
expectation of confidentiality from the XYZ-CERT. They may or
may not have legal rights to confidentiality; such rights will
of course be respected where they exist.
Information being considered for release will be classified as
follows:
- Private user information is information about particular
users, or in some cases, particular applications, which
must be considered confidential for legal, contractual,
and/or ethical reasons.
Private user information will be not be released in
identifiable form outside the XYZ-CERT, except as provided
for below. If the identity of the user is disguised, then
the information can be released freely (for example to show
a sample .cshrc file as modified by an intruder, or to
demonstrate a particular social engineering attack).
- Intruder information is similar to private user
information, but concerns intruders.
While intruder information, and in particular identifying
information, will not be released to the public (unless it
becomes a matter of public record, for example because
criminal charges have been laid), it will be exchanged
freely with system administrators and CSIRTs tracking an
incident.
- Private site information is technical information about
particular systems or sites.
It will not be released without the permission of the site
in question, except as provided for below.
- Vulnerability information is technical information about
vulnerabilities or attacks, including fixes and
workarounds.
Vulnerability information will be released freely, though
every effort will be made to inform the relevant vendor
before the general public is informed.
- Embarrassing information includes the statement that an
incident has occurred, and information about its extent or
severity. Embarrassing information may concern a site or
a particular user or group of users.
Embarrassing information will not be released without the
permission of the site or users in question, except as
provided for below.
- Statistical information is embarrassing information with
the identifying information stripped off.
Statistical information will be released at the discretion
of the Computing Services Department.
- Contact information explains how to reach system
administrators and CSIRTs.
Contact information will be released freely, except where
the contact person or entity has requested that this not
be the case, or where XYZ-CERT has reason to believe that
the dissemination of this information would not be
appreciated.
Potential recipients of information from the XYZ-CERT will be
classified as follows:
- Because of the nature of their responsibilities and
consequent expectations of confidentiality, members of XYZ
University management are entitled to receive whatever
information is necessary to facilitate the handling of
computer security incidents which occur in their
jurisdictions.
- Members of the Office of Rights and Responsibilities are
entitled to receive whatever information they request
concerning a computer security incident or related matter
which has been referred to them for resolution. The same is
true for the XYZ Security Department, when its assistance in
an investigation has been enlisted, or when the investigation
has been instigated at its request.
- System administrators at XYZ University who are members of
the CCSA are also, by virtue of their responsibilities,
trusted with confidential information. However, unless such
people are also members of XYZ-CERT, they will be given only
that confidential information which they must have in order
to assist with an investigation, or in order to secure their
own systems.
- Users at XYZ University are entitled to information which
pertains to the security of their own computer accounts,
even if this means revealing "intruder information", or
"embarrassing information" about another user. For
example, if account aaaa is cracked and the intruder attacks
account bbbb, user bbbb is entitled to know that aaaa was
cracked, and how the attack on the bbbb account was
executed. User bbbb is also entitled, if she or he requests
it, to information about account aaaa which might enable
bbbb to investigate the attack. For example, if bbbb was
attacked by someone remotely connected to aaaa, bbbb should
be told the provenance of the connections to aaaa, even
though this information would ordinarily be considered
private to aaaa. Users at XYZ University are entitled to be
notified if their account is believed to have been
compromised.
- The XYZ University community will receive no restricted
information, except where the affected parties have given
permission for the information to be disseminated.
Statistical information may be made available to the general
XYZ community. There is no obligation on the part of the
XYZ-CERT to report incidents to the community, though it may
choose to do so; in particular, it is likely that the
XYZ-CERT will inform all affected parties of the ways in
which they were affected, or will encourage the affected site
to do so.
- The public at large will receive no restricted information.
In fact, no particular effort will be made to communicate
with the public at large, though the XYZ-CERT recognizes
that, for all intents and purposes, information made
available to the XYZ University community is in effect made
available to the community at large, and will tailor the
information in consequence.
- The computer security community will be treated the same way
the general public is treated. While members of XYZ-CERT may
participate in discussions within the computer security
community, such as newsgroups, mailing lists (including the
full-disclosure list "bugtraq"), and conferences, they will
treat such forums as though they were the public at large.
While technical issues (including vulnerabilities) may be
discussed to any level of detail, any examples taken from
XYZ-CERT experience will be disguised to avoid identifying
the affected parties.
- The press will also be considered as part of the general
public. The XYZ-CERT will not interact directly with the
Press concerning computer security incidents, except to point
them toward information al