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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
Abstract
========
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.
Technical Details
=================
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:
options ISO
As a temporary workaround recompile the kernel with the
above option
commented out.
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:
http:
//www.NetBSD.org/guide/en/chap-kernel.html
Thanks To
=========
Christer Oberg of BitSec discovered and reported this
issue.
Christos Zoulas fixed the code.
Revision History
================
2007-03-29 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-S
A2007-004.txt.asc
Information about NetBSD and NetBSD security can be found
at
http://www.NetBSD.org/
and http://www.NetBSD.or
g/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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