ICMP Attacks against TCP
RFC 5927
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RFC - Informational
(July 2010; No errata)
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2015-10-14
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IETF
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plain text
pdf
html
bibtex
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WG state
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(None)
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Document shepherd |
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No shepherd assigned
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| IESG |
IESG state |
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RFC 5927 (Informational)
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Consensus Boilerplate |
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Unknown
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Telechat date |
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Responsible AD |
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Lars Eggert
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Send notices to |
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(None)
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Internet Engineering Task Force (IETF) F. Gont
Request for Comments: 5927 UTN/FRH
Category: Informational July 2010
ISSN: 2070-1721
ICMP Attacks against TCP
Abstract
This document discusses the use of the Internet Control Message
Protocol (ICMP) to perform a variety of attacks against the
Transmission Control Protocol (TCP). Additionally, this document
describes a number of widely implemented modifications to TCP's
handling of ICMP error messages that help to mitigate these issues.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5927.
Gont Informational [Page 1]
RFC 5927 ICMP Attacks against TCP July 2010
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Gont Informational [Page 2]
RFC 5927 ICMP Attacks against TCP July 2010
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. The Internet Control Message Protocol (ICMP) . . . . . . . 5
2.1.1. ICMP for IP version 4 (ICMPv4) . . . . . . . . . . . . 5
2.1.2. ICMP for IP version 6 (ICMPv6) . . . . . . . . . . . . 6
2.2. Handling of ICMP Error Messages . . . . . . . . . . . . . 6
2.3. Handling of ICMP Error Messages in the Context of IPsec . 7
3. Constraints in the Possible Solutions . . . . . . . . . . . . 8
4. General Counter-Measures against ICMP Attacks . . . . . . . . 10
4.1. TCP Sequence Number Checking . . . . . . . . . . . . . . . 10
4.2. Port Randomization . . . . . . . . . . . . . . . . . . . . 11
4.3. Filtering ICMP Error Messages Based on the ICMP Payload . 11
5. Blind Connection-Reset Attack . . . . . . . . . . . . . . . . 12
5.1. Description . . . . . . . . . . . . . . . . . . . . . . . 12
5.2. Attack-Specific Counter-Measures . . . . . . . . . . . . . 13
6. Blind Throughput-Reduction Attack . . . . . . . . . . . . . . 16
6.1. Description . . . . . . . . . . . . . . . . . . . . . . . 16
6.2. Attack-Specific Counter-Measures . . . . . . . . . . . . . 16
7. Blind Performance-Degrading Attack . . . . . . . . . . . . . . 16
7.1. Description . . . . . . . . . . . . . . . . . . . . . . . 16
7.2. Attack-Specific Counter-Measures . . . . . . . . . . . . . 18
7.3. The Counter-Measure for the PMTUD Attack in Action . . . . 22
7.3.1. Normal Operation for Bulk Transfers . . . . . . . . . 22
7.3.2. Operation during Path-MTU Changes . . . . . . . . . . 24
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