glibc: Information leak with LD_DEBUG

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200408-16 / glibc
Release Date	August 16, 2004
Latest Revision	May 28, 2006: 04
Impact	low
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
sys-libs/glibc	<= 2.3.2-r10	>= 2.3.2-r11	alpha arm hppa ia64 sparc s390
sys-libs/glibc	<= 2.3.3.20040420	>= 2.3.3.20040420-r1	x86 ppc
sys-libs/glibc	<= 2.3.3.20040420	>= 2.3.4.20040619-r1	mips
sys-libs/glibc	<= 2.3.4.20040619	>= 2.3.4.20040619-r1	AMD64
sys-libs/glibc	<= 2.3.4.20040605	>= 2.3.4.20040808	ppc64

Related bugreports: #59526

Synopsis

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

2. Impact Information

Background

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

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.

3. Resolution Information

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:

Code Listing 3.1: Resolution

# emerge sync

# emerge -pv your_version
# emerge your_version

4. References

CVE-2004-1453

Page updated August 16, 2004

Summary: This is a Gentoo Linux Security Advisory

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