Subject: NetBSD Security Advisory 2007-004: Insufficient length checking in iso(4)
To: None <current-users@NetBSD.org>
From: NetBSD Security-Officer <firstname.lastname@example.org>
Date: 03/29/2007 22:05:52
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NetBSD Security Advisory 2007-004
Topic: Insufficient length checking in iso(4)
Version: NetBSD-current: source prior to March 29, 2007
NetBSD 4.0_BETA2: affected
NetBSD 3.1: affected
NetBSD 3.0.*: affected
NetBSD 3.0: affected
NetBSD 2.1: affected
NetBSD 2.0.*: affected
NetBSD 2.0: affected
Severity: Local denial of service, Local root compromise
Fixed: NetBSD-current: March 29, 2007
NetBSD-4 branch: March 29, 2007
NetBSD-3-1 branch: March 29, 2007
NetBSD-3-0 branch: March 29, 2007
NetBSD-3 branch: March 29, 2007
NetBSD-2-1 branch: March 29, 2007
NetBSD-2-0 branch: March 29, 2007
NetBSD-2 branch: March 29, 2007
Due to insufficient length checking in iso(4) it is possible for a local
user to cause an overflow, resulting in a local denial of service or
local root compromise.
This vulnerability has been assigned CVE reference CVE-2007-1677.
A number of functions in the iso(4) code including clnp_route() do not
validate the length of arguments passed. As a result of this a user
could supply a bad 'sockaddr' structure to clnp_route() via connect(2).
This can lead to a root compromise if exploited correctly or a denial
of service (panic).
Solutions and Workarounds
Kernels with the ISO protocol family support are affected, including the
default GENERIC kernel install. Users of affected NetBSD versions are highly
recommended to upgrade their kernel.
Only kernels compiled with the following option are vulnerable to this issue:
As a temporary workaround recompile the kernel with the above option
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 sys/netiso/clnp_subr.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:
Christer Oberg of BitSec discovered and reported this issue.
Christos Zoulas fixed the code.
2007-03-29 Initial release
Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at
Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.org/ and http://www.NetBSD.org/Security/.
Copyright 2007, The NetBSD Foundation, Inc. All Rights Reserved.
Redistribution permitted only in full, unmodified form.
$NetBSD: NetBSD-SA2007-004.txt,v 1.1 2007/03/29 08:21:51 adrianp Exp $
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