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Posted on 23 May 2007
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FreeBSD-SA-07:04.file Security Advisory
The FreeBSD Project
Topic: Heap overflow in file(1)
Category: contrib
Module: file
Announced: 2007-05-23
Affects: All FreeBSD releases.
Corrected: 2007-05-23 16:12:51 UTC (RELENG_6, 6.2-STABLE)
2007-05-23 16:13:07 UTC (RELENG_6_2, 6.2-RELEASE-p5)
2007-05-23 16:13:20 UTC (RELENG_6_1, 6.1-RELEASE-p17)
2007-05-23 16:12:10 UTC (RELENG_5, 5.5-STABLE)
2007-05-23 16:12:35 UTC (RELENG_5_5, 5.5-RELEASE-p13)
CVE Name: CVE-2007-1536
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 file(1) utility attempts to classify file system objects based on
filesystem, magic number and language tests.
The libmagic(3) library provides most of the functionality of file(1)
and may be used by other applications.
II. Problem Description
When writing data into a buffer in the file_printf function, the length
of the unused portion of the buffer is not correctly tracked, resulting
in a buffer overflow when processing certain files.
III. Impact
An attacker who can cause file(1) to be run on a maliciously constructed
input can cause file(1) to crash. It may be possible for such an attacker
to execute arbitrary code with the privileges of the user running file(1).
The above also applies to any other applications using the libmagic(3)
library.
IV. Workaround
No workaround is available, but systems where file(1) and other
libmagic(3)-using applications are never run on untrusted input are not
vulnerable.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to 5-STABLE, or 6-STABLE, or to the
RELENG_6_2, RELENG_6_1, or RELENG_5_5 security branch dated after the
correction date.
2) To patch your present system:
The following patches have been verified to apply to FreeBSD 5.5, 6.1,
and 6.2 systems.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 5.5]
# fetch http://security.FreeBSD.org/patches/SA-07:04/file5.patch
# fetch http://security.FreeBSD.org/patches/SA-07:04/file5.patch.asc
[FreeBSD 6.1 and 6.2]
# fetch http://security.FreeBSD.org/patches/SA-07:04/file6.patch
# fetch http://security.FreeBSD.org/patches/SA-07:04/file6.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/lib/libmagic
# make obj && make depend && make && 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
src/contrib/file/file.h 1.1.1.7.2.1
src/contrib/file/funcs.c 1.1.1.1.2.1
src/contrib/file/magic.c 1.1.1.1.2.1
RELENG_5_5
src/UPDATING 1.342.2.35.2.13
src/sys/conf/newvers.sh 1.62.2.21.2.15
src/contrib/file/file.h 1.1.1.7.8.1
src/contrib/file/funcs.c 1.1.1.1.8.1
src/contrib/file/magic.c 1.1.1.1.8.1
RELENG_6
src/contrib/file/file.h 1.1.1.8.2.1
src/contrib/file/funcs.c 1.1.1.2.2.1
src/contrib/file/magic.c 1.1.1.2.2.1
RELENG_6_2
src/UPDATING 1.416.2.29.2.8
src/sys/conf/newvers.sh 1.69.2.13.2.8
src/contrib/file/file.h 1.1.1.8.8.1
src/contrib/file/funcs.c 1.1.1.2.8.1
src/contrib/file/magic.c 1.1.1.2.8.1
RELENG_6_1
src/UPDATING 1.416.2.22.2.19
src/sys/conf/newvers.sh 1.69.2.11.2.19
src/contrib/file/file.h 1.1.1.8.6.1
src/contrib/file/funcs.c 1.1.1.2.6.1
src/contrib/file/magic.c 1.1.1.2.6.1
- -------------------------------------------------------------------------
VII. References
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-1536
The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-07:04.file.asc
