Deprecation of Type 0 Routing Headers in IPv6
RFC 5095
Document | Type | RFC - Proposed Standard (December 2007; No errata) | |
---|---|---|---|
Authors | George Neville-Neil , Pekka Savola , Joe Abley | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5095 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Jari Arkko | ||
Send notices to | (None) |
Network Working Group J. Abley Request for Comments: 5095 Afilias Updates: 2460, 4294 P. Savola Category: Standards Track CSC/FUNET G. Neville-Neil Neville-Neil Consulting December 2007 Deprecation of Type 0 Routing Headers in IPv6 Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Abstract The functionality provided by IPv6's Type 0 Routing Header can be exploited in order to achieve traffic amplification over a remote path for the purposes of generating denial-of-service traffic. This document updates the IPv6 specification to deprecate the use of IPv6 Type 0 Routing Headers, in light of this security concern. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Deprecation of RH0 . . . . . . . . . . . . . . . . . . . . . . 3 4. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. Ingress Filtering . . . . . . . . . . . . . . . . . . . . . 3 4.2. Firewall Policy . . . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 8.2. Informative References . . . . . . . . . . . . . . . . . . 5 Abley, et al. Standards Track [Page 1] RFC 5095 Deprecation of RH0 December 2007 1. Introduction [RFC2460] defines an IPv6 extension header called "Routing Header", identified by a Next Header value of 43 in the immediately preceding header. A particular Routing Header subtype denoted as "Type 0" is also defined. Type 0 Routing Headers are referred to as "RH0" in this document. A single RH0 may contain multiple intermediate node addresses, and the same address may be included more than once in the same RH0. This allows a packet to be constructed such that it will oscillate between two RH0-processing hosts or routers many times. This allows a stream of packets from an attacker to be amplified along the path between two remote routers, which could be used to cause congestion along arbitrary remote paths and hence act as a denial-of-service mechanism. An 88-fold amplification has been demonstrated using this technique [CanSecWest07]. This attack is particularly serious in that it affects the entire path between the two exploited nodes, not only the nodes themselves or their local networks. Analogous functionality may be found in the IPv4 source route option, but the opportunities for abuse are greater with RH0 due to the ability to specify many more intermediate node addresses in each packet. The severity of this threat is considered to be sufficient to warrant deprecation of RH0 entirely. A side effect is that this also eliminates benign RH0 use-cases; however, such applications may be facilitated by future Routing Header specifications. Potential problems with RH0 were identified in 2001 [Security]. In 2002 a proposal was made to restrict Routing Header processing in hosts [Hosts]. These efforts resulted in the modification of the Mobile IPv6 specification to use the type 2 Routing Header instead of RH0 [RFC3775]. Vishwas Manral identified various risks associated with RH0 in 2006 including the amplification attack; several of these vulnerabilities (together with other issues) were later documented in [RFC4942]. A treatment of the operational security implications of RH0 was presented by Philippe Biondi and Arnaud Ebalard at the CanSecWest conference in Vancouver, 2007 [CanSecWest07]. This presentation resulted in widespread publicity for the risks associated with RH0. This document updates [RFC2460] and [RFC4294]. Abley, et al. Standards Track [Page 2] RFC 5095 Deprecation of RH0 December 2007 2. Definitions RH0 in this document denotes the IPv6 Extension Header type 43Show full document text