[FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-13:02.libc

FreeBSD Security Advisories security-advisories at freebsd.org
Tue Feb 19 14:04:05 UTC 2013

Hash: SHA1

FreeBSD-SA-13:02.libc                                       Security Advisory
                                                          The FreeBSD Project

Topic:          glob(3) related resource exhaustion

Category:       core
Module:         libc
Announced:      2013-02-19
Affects:        All supported versions of FreeBSD.
Corrected:      2013-02-05 09:53:32 UTC (stable/7, 7.4-STABLE)
                2013-02-19 13:27:20 UTC (releng/7.4, 7.4-RELEASE-p12)
                2013-02-05 09:53:32 UTC (stable/8, 8.3-STABLE)
                2013-02-19 13:27:20 UTC (releng/8.3, 8.3-RELEASE-p6)
                2013-02-05 09:53:32 UTC (stable/9, 9.1-STABLE)
                2013-02-19 13:27:20 UTC (releng/9.0, 9.0-RELEASE-p6)
                2013-02-19 13:27:20 UTC (releng/9.1, 9.1-RELEASE-p1)
CVE Name:       CVE-2010-2632

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:http://security.FreeBSD.org/>.

I.   Background

The glob(3) function is a pathname generator that implements the rules for
file name pattern matching used by the shell.

II.  Problem Description

GLOB_LIMIT is supposed to limit the number of paths to prevent against
memory or CPU attacks.  The implementation however is insufficient.

III. Impact

An attacker that is able to exploit this vulnerability could cause excessive
memory or CPU usage, resulting in a Denial of Service.  A common target for
a remote attacker could be ftpd(8).

IV.  Workaround

No workaround is available.

V.   Solution

Perform one of the following:

1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

2) To update your vulnerable system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch http://security.FreeBSD.org/patches/SA-13:02/libc.patch
# fetch http://security.FreeBSD.org/patches/SA-13:02/libc.patch.asc
# gpg --verify libc.patch.asc

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

Recompile the operating system using buildworld and installworld as
described in <URL:http://www.FreeBSD.org/handbook/makeworld.html>.

Restart all daemons, or reboot the system.

3) To update your vulnerable system via a binary patch:

Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

Restart all daemons, or reboot the system.

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Branch/path                                                      Revision
- -------------------------------------------------------------------------
stable/7/                                                         r246357
releng/7.4/                                                       r246989
stable/8/                                                         r246357
releng/8.3/                                                       r246989
stable/9/                                                         r246357
releng/9.0/                                                       r246989
releng/9.1/                                                       r246989
- -------------------------------------------------------------------------

VII. References


The latest revision of this advisory is available at
Version: GnuPG v1.4.12 (FreeBSD)


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