XEP-0268: Incident Handling

WARNING: This Standards-Track document is Experimental. Publication as an XMPP Extension Protocol does not imply approval of this proposal by the XMPP Standards Foundation. Implementation of the protocol described herein is encouraged in exploratory implementations, but production systems are advised to carefully consider whether it is appropriate to deploy implementations of this protocol before it advances to a status of Draft.

Table of Contents

1. Introduction

As XMPP technologies have been deployed more widely, the open XMPP network has become a more significant target for attacks. This specification defines ways for XMPP server deployments to share information with each other and therefore to handle such attacks in a more real-time fashion. In particular, it defines a way to use the IODEF format (defined in RFC 5070 [1] and produced by the IETF's INCH Working Group) as the basis for sharing incident reports among XMPP server deployments. (For some related considerations, see RFC 2350 [2] and RFC 3067 [3].)

2. Interactions

This document defines several interactions (similar to those in RFC 6045 [4]) between XMPP server deployments with respect to incident handling. These interactions are transported using the XMPP <iq/> stanza as described below.

1. The <report/> element (contained in an <iq/> stanza of type "set" or, in response to an <inquiry/> element, of type "result") describes the nature of an incident and also flags the 'status' of the incident as "new", "updated", or "resolved"; it is sent from one server to another for informative purposes (sometimes in reply to the <inquiry/> element) but without requesting assistance (for which see the <request/> element).

2. The <inquiry/> element (contained in an <iq/> stanza of type "get") asks for information about an incident; it is expected that the reply will contain a <report/> element.

3. The <request/> element (contained in an <iq/> stanza of type "get") asks for assistance in resolving an incident.

4. The <response/> element (contained in an <iq/> stanza of type "result") provides assistance in resolving an incident.

3. Report Format and Processing

An incident report consists of an XMPP <iq/> stanza of type "set" or "result" containing an IODEF document. An example is shown below.

Example 1. An incident report

<iq from='jabber.org' id='vk2x91g47 to='im.flosoft.biz' type='set'>
  <Incident xmlns='urn:ietf:params:xml:ns:iodef-1.0'
            purpose='reporting'>
    <IncidentID name='jabber.org'>4BF5D2CE-7C90-4860-BEF2-43A7D777D5FF</IncidentID>
    <StartTime>2009-04-13T19:05:20Z</StartTime>
    <EndTime>2009-04-13T19:27:22Z</EndTime>
    <ReportTime>2009-04-13T19:31:07Z</ReportTime>
    <Description xml:lang='en'>lots of MUC spammers from abuse.lit!</Description>
    <Contact role='admin' type='person'>
      <AdditionalData>
        <jid xmlns='urn:xmpp:incident:2'>stpeter@jabber.org</jid>
      </AdditionalData>
    </Contact>
    <Contact role='admin' type='person'>
      <AdditionalData>
        <jid xmlns='urn:xmpp:incident:2'>stpeter@jabber.org</jid>
      </AdditionalData>
    </Contact>
    <Contact role='ext-type' ext-type='chatroom'>
      <AdditionalData>
        <jid xmlns='urn:xmpp:incident:2'>operators@muc.xmpp.org</jid>
      </AdditionalData>
    </Contact>
    <RelatedActivity>
      <IncidentID name='im.example.com'>133BCE2E-E669-4ECE-B0F8-766B9E65630D</IncidentID>
    </RelatedActivity>
    <Assessment>
      <Impact lang='en' severity='medium' completion='succeeded' type='dos'/>
    </Assessment>
    <EventData>
      <Flow>
        <System category='source'>
          <Node>
            <Address category='ext-category' ext-category='xmpp'>abuser@abuse.lit</Address>
            <Counter type='ext-type' ext-type='xmpp-presence'>123</Counter>
          </Node>
          <Node>
            <Address category='ext-category' ext-category='xmpp'>luser27@abuse.lit</Address>
            <Counter type='ext-type' ext-type='xmpp-presence'>47</Counter>
          </Node>
        </System>
        <System category='target'>
          <Node>
            <Address category='ext-category' ext-category='xmpp'>jdev@conference.jabber.org</Address>
            <Address category='ext-category' ext-category='xmpp'>jabber@conference.jabber.org</Address>
            <NodeRole category='ext-category' ext-category='xmpp-muc'/>
          </Node>
        </System>
      </Flow>
      <info>
        <category>muc</category>
        <type>presence</type>
        <type>long-messages</type>
  </Incident>
</iq>
  

If the report is contained in an <iq/> stanza of type "set" and the recipient of the report is able to process it, it MUST return an <iq/> stanza of type "result". Error handling will be defined in a future version of this specification.

4. Inquiry Format and Processing

To follow.

5. Request Format and Processing

To follow.

6. Response Format and Processing

To follow.

7. Internationalization Considerations

The <jid/> element qualified by the 'urn:xmpp:incident:2' namespace is a "JID slot" as described in rfc6122bis [5].

8. Security Considerations

It is RECOMMENDED for a server deployment to exchange incident reports only with peer servers that it trusts, for example peers that are in its "server roster" as described in Server Buddies [6].

This technology is designed to help mitigate attacks on the XMPP network. However, incident reporting is itself vulnerable to the following attacks:

• False reports could lead a server to deny service to legitimate users or peer servers (see also Best Practices to Discourage Denial of Service Attacks [7]). To help mitigate such attacks, a server SHOULD treat with caution any incident reports that it might receive from untrusted entities.
• If traffic between two servers is not protected using Transport Layer Security (TLS), a passive eavesdropper could gain access to incident reports and therefore adjust its behavior in response. To prevent such attacks, servers SHOULD use TLS.

Use of the XMPP channel is convenient for communication among XMPP servers; however, if a denial of service attack is severe enough then that channel itself might be unusable.

Unless explicitly configured to do so, a receiving server SHOULD NOT automatically modify its configuration based on receipt of an incident report, even from a trusted server, but instead SHOULD prompt the human administrators so that they can take appropriate action.

A receiving server MAY accept incident reports from peers that are not on its "trust list", but SHOULD treat such reports with caution and provide them to the human administrator(s) of the server.

A receiving server MAY forward reports that it receives to other servers it trusts.

9. IANA Considerations

This document might require interaction with the Internet Assigned Numbers Authority (IANA) [8] to register various IODEF extension attributes.

10. XMPP Registrar Considerations

11. XML Schema

<?xml version='1.0' encoding='UTF-8'?>

<xs:schema
    xmlns:xs='http://www.w3.org/2001/XMLSchema'
    targetNamespace='urn:xmpp:incident:2'
    xmlns='urn:xmpp:incident:2'
    elementFormDefault='qualified'>

  <xs:element name='jid' type='xs:string'/>

</xs:schema>
  

Appendices

Appendix A: Document Information

Series: XEP
Number: 0268
Publisher: XMPP Standards Foundation
Status: Experimental
Type: Standards Track
Version: 0.4
Last Updated: 2012-04-17
Approving Body: XMPP Council
Dependencies: XMPP Core
Supersedes: None
Superseded By: None
Short Name: NOT_YET_ASSIGNED
Source Control: HTML
This document in other formats: XML  PDF

Appendix B: Author Information

Appendix C: Legal Notices

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Appendix E: Discussion Venue

There exists a special venue for discussion related to the technology described in this document: the <operators@xmpp.org> mailing list.

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".

Appendix G: Notes

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

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