Home » Mailing list archives » netbsd-announce » 2006 » April » 12

NetBSD Security Advisory 2006-011: IPSec replay attack

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
[view in full thread]
From: NetBSD Security-Officer <security-officer@...>
Subject: NetBSD Security Advisory 2006-011: IPSec replay attack
Date: Wednesday, April 12, 2006 - 10:33 pm

-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1


		 NetBSD Security Advisory 2006-011

		 =================================


Topic:		IPSec replay attack


Version:	NetBSD-current:	source prior to March 23, 2006

		NetBSD 3.0:	affected

		NetBSD 2.1:	affected

		NetBSD 2.0.*:	affected

		NetBSD 2.0:	affected


Severity:	Systems could be vulnerable to a replay attack


Fixed:		NetBSD-current:		March 23, 2006

		NetBSD-3-0 branch:	March 28, 2006

						(3.0.1 will include the fix)

		NetBSD-3 branch:	March 28, 2006

		NetBSD-2-1 branch:	March 30, 2006

						(2.1.1 will include the fix)

		NetBSD-2-0 branch:	March 30, 2006

						(2.0.4 will include the fix)

		NetBSD-2 branch:	March 30, 2006


Abstract

========


A vulnerability was found in the fast_ipsec(4) stack that renders the

IPSec anti-replay service ineffective under certain circumstances.


If the upper layer protocol doesn't provide any anti-packet replay

verification (for example, UDP) the system may be vulnerable to a

replay attack.


This vulnerability has been assigned CVE reference CVE-2006-0905.


Technical Details

=================


The anti-replay service specifies an algorithm for preventing

injection of previously received packets from unknown parties

(the replay attack).


Due to a programming error in the fast_ipsec(4) stack, the Sequence

Number associated with a SA was not being updated, thus allowing

packets to bypass any sequence verification check.


Solutions and Workarounds

=========================


The default configuration of NetBSD does not ship with FAST_IPSEC enabled.


For all NetBSD versions, you need to obtain fixed kernel sources,

rebuild and install the new kernel, and reboot the system.


The fixed source may be obtained from the NetBSD CVS repository.


The following instructions briefly summarise how to upgrade your

kernel.  In these instructions, replace:


  ARCH     with your architecture (from uname -m), and

  KERNCONF with the name of your kernel configuration file.


To update from CVS, re-build, and re-install the kernel:


	# cd src

	# cvs update -d -P sys/netipsec/xform_esp.c

	# ./build.sh kernel=KERNCONF

	# mv /netbsd /netbsd.old

	# cp sys/arch/ARCH/compile/obj/KERNCONF/netbsd /netbsd

	# shutdown -r now


For more information on how to do this, see:


   http://www.NetBSD.org/guide/en/chap-kernel.html


Thanks To

=========


Pawel Jakub Dawidek is credited with the discovery of this issue

The FreeBSD Project for initial notification via FreeBSD-SA-06:11.ipsec

Rui Paulo for importing the fixes into NetBSD


Revision History

================


	2006-04-12	Initial release


More Information

================


Advisories may be updated as new information becomes available.

The most recent version of this advisory (PGP signed) can be found at

  ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2006-011.tx...


Information about NetBSD and NetBSD security can be found at

http://www.NetBSD.org/ and http://www.NetBSD.org/Security/.


Copyright 2006, The NetBSD Foundation, Inc.  All Rights Reserved.

Redistribution permitted only in full, unmodified form.


$NetBSD: NetBSD-SA2006-011.txt,v 1.8 2006/04/12 22:53:07 adrianp Exp $


-----BEGIN PGP SIGNATURE-----

Version: GnuPG v1.4.3 (NetBSD)


iQCVAwUBRD2E3j5Ru2/4N2IFAQKr/AP+KIHPPTfJQPSJLlZvvvUgapbaPMTWaC48

T2JwVcdQmxka8G36k/mKeI92Jenk63R557NEgtqUjEsDi+3862HcKQSXSd+Jzjfa

9Ec2ORyKlE/IRnsRtCb9NxjGqYg3I+ti8ENKs9lBqw4XJkcgDdkI0KJ8NWnKnD0f

Rz6FoeFdYgc=

=PLJl

-----END PGP SIGNATURE-----
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
Messages in current thread:
NetBSD now has native pthreads!, Jan Schaumann, (Sun Jan 19, 6:14 pm)
NetBSD Security Advisory 2007-007: BIND cryptographically we..., NetBSD Security-Officer, (Thu Sep 13, 5:56 pm)
The pkgsrc-2008Q2 Release, Alistair Crooks, (Sat Jul 26, 3:45 am)
Summer of Code student applications period extended, Jan Schaumann, (Wed Apr 2, 1:36 am)
Summary of Changes to the NetBSD Packages Collection in May ..., Alistair Crooks, (Tue Jun 3, 4:18 pm)
NetBSD Security Advisory 2008-003: IPsec in IPv6 Denial of S..., NetBSD Security-Officer, (Thu Feb 28, 7:37 pm)
Summary of Changes to the Packages Collection in November an..., Alistair Crooks, (Sun Feb 1, 9:16 pm)
Announcing NetBSD 5.0, Soren Jacobsen, (Wed Apr 29, 5:49 pm)
anoncvs service unavailable until further notice, Christos Zoulas, (Thu Dec 23, 2:27 pm)
Timelines for upcoming releases, James Chacon, (Mon May 2, 6:51 pm)
NetBSD Security Advisory 2005-001: Crypto leaks across Hyper..., NetBSD Security-Officer, (Thu Jun 30, 6:12 pm)
cvsweb offline, SODA Noriyuki, (Thu Aug 11, 10:46 am)
Announcing update 2.0.3 - source only, James Chacon, (Mon Oct 31, 11:52 am)
[ANNOUNCE] pkgsrc-users mailing list, Johnny C. Lam, (Thu Feb 23, 7:47 pm)
NetBSD Security Advisory 2006-007: mail(1) creates record fi..., NetBSD Security-Officer, (Wed Mar 29, 9:31 pm)
NetBSD Security Advisory 2006-011: IPSec replay attack, NetBSD Security-Officer, (Wed Apr 12, 10:33 pm)
Promote BSD and Share the Wealth, Chris Coleman, (Thu Apr 18, 7:38 pm)
New Developers, Jan Schaumann, (Mon Jul 1, 5:55 pm)
Announcing the release of NetBSD 3.0.1, Matthias Scheler, (Mon Jul 24, 2:02 pm)
Organizational Changes to the NetBSD Project, Alistair Crooks, (Fri Sep 1, 3:36 am)
NetBSD 5.0_RC2 binaries available for download, Soren Jacobsen, (Tue Feb 10, 11:43 pm)
NetBSD developer's summit and hackathon, Jan Schaumann, (Sat Oct 4, 2:02 pm)
NetBSD Security Advisory 2009-010: ISC dhclient subnet-mask ..., NetBSD Security Officer, (Tue Jul 14, 5:31 pm)