FreeBSD IPv6 secsockopt(2) Input Validation Flaws May Disclose Memory to Local Users or Permit Local Denial of Service
|
|
SecurityTracker Alert ID: 1009586
|
|
CVE Reference: CAN-2004-0370
(Links to External Site)
|
Date: Mar 29 2004
|
Impact: Denial of service via local system, Disclosure of authentication information, Disclosure of system information, Disclosure of user information
|
Fix Available: Yes
Vendor Confirmed: Yes
|
Version(s): 5.2
|
Description: An input validation vulnerability was reported in FreeBSD in the IPv6 setsockopt(2) call. A local user can view kernel memory or trigger a system panic.
FreeBSD reported that there is a flaw in the KAME IPv6 implementation, but that the flaw only affects FreeBSD. FreeBSD indicates
that errors in processing some IPv6 socket options in the setsockopt(2) system call may permit the calling application to be able
to gain read access to memory locations. A local user can read portions of kernel memory or cause a kernel panic.
|
Impact: A local user may be able to read portions of kernel memory.
A local user may be able to cause a system panic.
The specific impact depends on the application that uses the affected system call.
|
Solution: The vendor indicates that you should do one of the following [quoted]:
1) Upgrade your vulnerable system to the RELENG_5_2 security
branch dated after the correction date.
2) To patch your present system:
a) Download the relevant patch from the location
below, and verify the detached PGP signature using your PGP utility.
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch
#
fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch.asc
b) Execute the following commands as root:
#
cd /usr/src
# patch < /path/to/patch
c) Recompile the kernel as described in http://www.freebsd.org/handbook/kernelconfig.html
and reboot the system.
d) Install updated kernel headers.
# cd /usr/src/include
# make install
|
Vendor URL: www.freebsd.org/ (Links to External Site)
|
Cause: Input validation error
|
Underlying OS: UNIX (FreeBSD)
|
Reported By: FreeBSD Security Advisories <security-advisories@freebsd.org>
|
Message History:
None.
|
Source Message Contents
|
Date: Mon, 29 Mar 2004 06:15:26 -0800 (PST)
From: FreeBSD Security Advisories <security-advisories@freebsd.org>
Subject: FreeBSD Security Advisory FreeBSD-SA-04:06.ipv6
|
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
=============================================================================
FreeBSD-SA-04:06.ipv6 Security Advisory
The FreeBSD Project
Topic: setsockopt(2) IPv6 sockets input validation error
Category: core
Module: kernel
Announced: 2004-03-29
Credits: Katsuhisa ABE, Colin Percival
Affects: FreeBSD 5.2-RELEASE
Corrected: 2004-03-29 14:01:33 UTC (RELENG_5_2, 5.2.1-RELEASE-p4)
CVE Name: CAN-2004-0370
FreeBSD only: YES
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit
<URL:http://www.freebsd.org/security/>.
I. Background
IPv6 is a new Internet Protocol, designed to replace (and avoid many of
the problems with) the current Internet Protocol (version 4). FreeBSD
uses the KAME Project IPv6 implementation.
Applications may manipulate the behavior of an IPv6 socket using the
setsockopt(2) system call.
II. Problem Description
A programming error in the handling of some IPv6 socket options within
the setsockopt(2) system call may result in memory locations being
accessed without proper validation. While the problem originates in
code from the KAME Project, it does not affect other operating systems.
III. Impact
It may be possible for a local attacker to read portions of kernel
memory, resulting in disclosure of sensitive information. A local
attacker can cause a system panic.
IV. Workaround
Do one of the following:
1) Disable IPv6 entirely by following these steps:
- Remove or comment out any lines mentioning `INET6' from your
kernel configuration file, and recompile your kernel as described
in <URL:http://www.freebsd.org/handbook/kernelconfig.html>.
- Reboot your system.
2) If all untrusted users are confined within a jail(8), ensure that
the security.jail.socket_unixiproute_only sysctl is set to 1 and
verify that no IPv6 sockets are currently open:
# sysctl security.jail.socket_unixiproute_only=1
# sockstat -6
This will restrict jailed processes to creating UNIX domain, IPv4, and
routing sockets, which are not vulnerable to this problem; note however
that processes inside a jail may still be able to inherit IPv6 sockets
from outside the jail, so this may not be sufficient for all systems.
V. Solution
Do one of the following:
1) Upgrade your vulnerable system to the RELENG_5_2 security branch
dated after the correction date.
2) To patch your present system:
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile the kernel as described in
<URL:http://www.freebsd.org/handbook/kernelconfig.html> and reboot the
system.
d) Install updated kernel headers.
# cd /usr/src/include
# make install
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
Branch Revision
Path
- -------------------------------------------------------------------------
RELENG_5_2
src/UPDATING 1.282.2.12
src/sys/netinet6/ip6_output.c 1.71.2.2
src/sys/netinet/ip6.h 1.10.2.1
src/sys/conf/newvers.sh 1.56.2.11
- -------------------------------------------------------------------------
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)
iD8DBQFAaC6kFdaIBMps37IRAiCBAJ9ATb8FTKysuJvwlU8E0YOArWwP1gCcCCpw
rK7VXiZuLwD1zZmBepSHCt4=
=FLqJ
-----END PGP SIGNATURE-----
_______________________________________________
freebsd-security-notifications@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications
To unsubscribe, send any mail to "freebsd-security-notifications-unsubscribe@freebsd.org"
|
|
