| Summary: | sys-apps/file Buffer overflow (CVE-2007-2799) | ||
|---|---|---|---|
| Product: | Gentoo Security | Reporter: | Sune Kloppenborg Jeppesen (RETIRED) <jaervosz> |
| Component: | Vulnerabilities | Assignee: | Gentoo Security <security> |
| Status: | RESOLVED FIXED | ||
| Severity: | major | CC: | lars, sgtphou, solar |
| Priority: | High | ||
| Version: | unspecified | ||
| Hardware: | All | ||
| OS: | Linux | ||
| URL: | https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=241022 | ||
| Whiteboard: | A2 [glsa] jaervosz | ||
| Package list: | Runtime testing required: | --- | |
I got this email earlier today and my first thought was dupe :) *** This bug has been marked as a duplicate of bug 171452 *** It's not a dupe. The patch for CVE-2007-1536 introduced another issue. Information from Redhat bug:
Colin Percival discovered that the fix for CVE-2007-1536 created an integer
overflow flaw in file. This new flaw has been assigned CVE-2007-2799.
Here is the information from Colin:
+ len = ms->o.size - ms->o.left;
+ /* * 4 is for octal representation, + 1 is for NUL */
+ psize = len * 4 + 1;
+ assert(psize > len);
On a 32-bit system, if len is 1.35GB, len * 4 + 1 = 5.4GB == 1.4GB, so
the assert will pass. The buffer will then be overflowed (by as much
as the attacker wants, although of course he'll run into unwriteable
addresses eventually). This looks pretty exploitable...
I think the right solution is to apply
- assert(psize > len);
+ if (len > (SIZE_T_MAX - 1) / 4) {
+ file_oomem(ms);
+ return NULL;
+ }
and add
#include <limits.h> to the top (in place of the #include <assert.h> which
the earlier patch adds).
This needs to be fixed. The fix for the last two bumps were bogus. Somewhat a shame fbsd had to figure this out and our own people did not. Credits to the fbsd team. file-4.21 is in portage Thx Mike. Arches please test and mark stable. Target keywords are: file-4.21.ebuild:KEYWORDS="alpha amd64 arm hppa ia64 m68k mips ppc ppc64 s390 sh sparc ~sparc-fbsd x86 ~x86-fbsd" Stable for HPPA. x86/amd64 stable alpha/ia64 stable ppc64 stable ppc stable sparc stable. 200705-25, thanks everybody mips stable. *** Bug 181099 has been marked as a duplicate of this bug. *** |
Seems like the fix to CVE-2007-1536 introduced another issue: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGVGjhFdaIBMps37IRAgogAJ9o/0yCxtRi527rgvhg/BoC/AvEsQCfcwMX ABl7JIb1XiY6QKWQ6UfwlGA= =meQ0 -----END PGP SIGNATURE-----