exploit the possibilities
Home Files News &[SERVICES_TAB]About Contact Add New

FreeBSD Security Advisory - rtld

FreeBSD Security Advisory - rtld
Posted Dec 3, 2009
Site security.freebsd.org

FreeBSD Security Advisory - The run-time link-editor, rtld, links dynamic executable with their needed libraries at run-time. It also allows users to explicitly load libraries via various LD_ environmental variables.

tags | advisory
systems | freebsd
advisories | CVE-2009-3555
SHA-256 | 43cd0a5c752f6ee28c98c000a73357ee02baaf6cfca10e1ff8d34ae1cd5fecd1

FreeBSD Security Advisory - rtld

Change Mirror Download
Hash: SHA1

FreeBSD-SA-09:16.rtld Security Advisory
The FreeBSD Project

Topic: Improper environment sanitization in rtld(1)

Category: core
Module: rtld
Announced: 2009-12-03
Affects: FreeBSD 7.0 and later.
Corrected: 2009-12-01 02:59:22 UTC (RELENG_8, 8.0-STABLE)
2009-12-03 09:18:40 UTC (RELENG_8_0, 8.0-RELEASE-p1)
2009-12-01 03:00:16 UTC (RELENG_7, 7.2-STABLE)
2009-12-03 09:18:40 UTC (RELENG_7_2, 7.2-RELEASE-p5)
2009-12-03 09:18:40 UTC (RELENG_7_1, 7.1-RELEASE-p9)
CVE Name: CVE-2009-4146, CVE-2009-4147

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 run-time link-editor, rtld, links dynamic executable with their
needed libraries at run-time. It also allows users to explicitly
load libraries via various LD_ environmental variables.

II. Problem Description

When running setuid programs rtld will normally remove potentially
dangerous environment variables. Due to recent changes in FreeBSD
environment variable handling code, a corrupt environment may
result in attempts to unset environment variables failing.

III. Impact

An unprivileged user who can execute programs on a system can gain
the privileges of any setuid program which he can run. On most
systems configurations, this will allow a local attacker to execute
code as the root user.

IV. Workaround

No workaround is available, but systems without untrusted local users,
where all the untrusted local users are jailed superusers, and/or where
untrusted users cannot execute arbitrary code (e.g., due to use of read
only and noexec mount options) are not affected.

Note that "untrusted local users" include users with the ability to
upload and execute web scripts (CGI, PHP, Python, Perl etc.), as they
may be able to exploit this issue.

V. Solution

Perform one of the following:

1) Upgrade your vulnerable system to 7-STABLE or 8-STABLE,
or to the RELENG_8_0, RELENG_7_2, or RELENG_7_1 security branch dated
after the correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 7.1, 7.2,
and 8.0 systems.

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

[FreeBSD 7.x]
# fetch http://security.FreeBSD.org/patches/SA-09:16/rtld7.patch
# fetch http://security.FreeBSD.org/patches/SA-09:16/rtld7.patch.asc

[FreeBSD 8.0]
# fetch http://security.FreeBSD.org/patches/SA-09:16/rtld.patch
# fetch http://security.FreeBSD.org/patches/SA-09:16/rtld.patch.asc

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/libexec/rtld-elf
# make obj && make depend && make && make install

NOTE: On the amd64 platform, the above procedure will not update the
ld-elf32.so.1 (i386 compatibility) run-time link-editor (rtld). On
amd64 systems where the i386 rtld are installed, the operating system
should instead be recompiled as described in

VI. Correction details

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


Branch Revision
- -------------------------------------------------------------------------
src/UPDATING 1.507.
src/UPDATING 1.507.
src/UPDATING 1.632.
- -------------------------------------------------------------------------


Branch/path Revision
- -------------------------------------------------------------------------
stable/7/ r199981
releng/7.2/ r200054
releng/7.1/ r200054
stable/8/ r199980
releng/8.0/ r200054
- -------------------------------------------------------------------------

VII. References


The latest revision of this advisory is available at
Version: GnuPG v1.4.10 (FreeBSD)

Login or Register to add favorites

File Archive:

September 2022

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Sep 1st
    23 Files
  • 2
    Sep 2nd
    12 Files
  • 3
    Sep 3rd
    0 Files
  • 4
    Sep 4th
    0 Files
  • 5
    Sep 5th
    10 Files
  • 6
    Sep 6th
    8 Files
  • 7
    Sep 7th
    30 Files
  • 8
    Sep 8th
    14 Files
  • 9
    Sep 9th
    26 Files
  • 10
    Sep 10th
    0 Files
  • 11
    Sep 11th
    0 Files
  • 12
    Sep 12th
    5 Files
  • 13
    Sep 13th
    28 Files
  • 14
    Sep 14th
    15 Files
  • 15
    Sep 15th
    17 Files
  • 16
    Sep 16th
    9 Files
  • 17
    Sep 17th
    0 Files
  • 18
    Sep 18th
    0 Files
  • 19
    Sep 19th
    12 Files
  • 20
    Sep 20th
    15 Files
  • 21
    Sep 21st
    20 Files
  • 22
    Sep 22nd
    13 Files
  • 23
    Sep 23rd
    12 Files
  • 24
    Sep 24th
    0 Files
  • 25
    Sep 25th
    0 Files
  • 26
    Sep 26th
    0 Files
  • 27
    Sep 27th
    0 Files
  • 28
    Sep 28th
    0 Files
  • 29
    Sep 29th
    0 Files
  • 30
    Sep 30th
    0 Files

Top Authors In Last 30 Days

File Tags


packet storm

© 2022 Packet Storm. All rights reserved.

Hosting By