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Fwd: [Full-Disclosure] [ GLSA 200408-16 ] glibc: Information leak with LD_DEBUG



This looks like a fairly serious local exploit. Comment?

:wes

Begin forwarded message:

From: Kurt Lieber <klieber@xxxxxxxxxx>
Date: 17 August 2004 09:12:04 EDT
To: gentoo-announce@xxxxxxxxxxxxxxxx
Cc: bugtraq@xxxxxxxxxxxxxxxxx, full-disclosure@xxxxxxxxxxxxxxxx, security-alerts@xxxxxxxxxxxxxxxxx
Subject: [Full-Disclosure] [ GLSA 200408-16 ] glibc: Information leak with LD_DEBUG


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Gentoo Linux Security Advisory                           GLSA 200408-16
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                                            http://security.gentoo.org/
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  Severity: Low
     Title: glibc: Information leak with LD_DEBUG
      Date: August 16, 2004
      Bugs: #59526
        ID: 200408-16

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Synopsis
========

glibc contains an information leak vulnerability allowing the debugging
of SUID binaries.

Background
==========

The GNU C library defines various Unix-like "system calls" and other
basic facilities needed for a standard POSIX-like application to
operate.

Affected packages
=================

    -------------------------------------------------------------------
     Package         /      Vulnerable      /               Unaffected
    -------------------------------------------------------------------
  1  sys-libs/glibc        <= 2.3.2-r10                   >= 2.3.2-r11
  2  sys-libs/glibc      <= 2.3.3.20040420        >= 2.3.3.20040420-r1
  3  sys-libs/glibc      <= 2.3.3.20040420        >= 2.3.4.20040619-r1
  4  sys-libs/glibc      <= 2.3.4.20040619        >= 2.3.4.20040619-r1
  5  sys-libs/glibc        <= 2.3.2-r10                    Vulnerable!
  6  sys-libs/glibc      <= 2.3.4.20040605                 Vulnerable!
    -------------------------------------------------------------------
     # Package 1 only applies to ALPHA, ARM, HPPA, IA64 and SPARC
       users.
     # Package 2 only applies to x86 and PPC users.
     # Package 3 only applies to MIPS users.
     # Package 4 only applies to AMD64 users.
     # Package 5 only applies to S390 users.
     # Package 6 only applies to PPC64 users.
    -------------------------------------------------------------------
     NOTE: Certain packages are still vulnerable. Users should migrate
           to another package if one is available or wait for the
           existing packages to be marked stable by their
           architecture maintainers.
    -------------------------------------------------------------------
     6 affected packages; please see the notes above...
    -------------------------------------------------------------------

Description
===========

Silvio Cesare discovered a potential information leak in glibc. It
allows LD_DEBUG on SUID binaries where it should not be allowed. This
has various security implications, which may be used to gain
confidentional information.

Impact
======

An attacker can gain the list of symbols a SUID application uses and
their locations and can then use a trojaned library taking precendence
over those symbols to gain information or perform further exploitation.

Workaround
==========

There is no known workaround at this time. All users are encouraged to
upgrade to the latest available version of glibc.

Resolution
==========

All glibc users should upgrade to the latest version:

# emerge sync

    # emerge -pv your_version
    # emerge your_version

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

http://security.gentoo.org/glsa/glsa-200408-16.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@xxxxxxxxxx or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2004 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/1.0