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

[Kurt Lieber <klieber () gentoo org>]

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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 () gentoo org 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

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