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Caldera Systems Security Advisory: glibc security problems

Jan 25, 2001, 21:53 (0 Talkback[s])

Date: Wed, 24 Jan 2001 13:04:50 -0700
From: Caldera Support Info sup-info@LOCUTUS4.CALDERASYSTEMS.COM
To: BUGTRAQ@SECURITYFOCUS.COM
Subject: Security update: CSSA-2001-007.0 glibc security problems


                   Caldera Systems, Inc.  Security Advisory

Subject:                glibc security problems
Advisory number:        CSSA-2001-007.0
Issue date:             2001 January, 23
Cross reference:

1. Problem Description

The ELF shared library loader that is part of glibc supports the LD_PRELOAD environment variable that lets a user request that additional shared libraries should be loaded when starting a program. Normally, this feature should be disabled for setuid applications because of its security implications.

However, the loader from glibc 2.1.1 and 2.1.3 will honor this variable even in setuid applications as long as it doesn't contain a slash. As a result, a user can ask that arbitrary libraries from ``system'' directories can be loaded (i.e. from those directories listed in /etc/ld.so.conf).

This is a serious security problem and can be exploited to overwrite arbitrary files on the system, for instance.

2. Vulnerable Versions

   System                       Package

   OpenLinux 2.3                All packages previous to
                                glibc-2.1.3-6OL

OpenLinux eServer 2.3.1 All packages previous to and OpenLinux eBuilder glibc-2.1.3-6S
OpenLinux eDesktop 2.4 All packages previous to glibc-2.1.3-6
3. Solution

Workaround

none

The proper solution is to upgrade to the latest packages.

4. OpenLinux 2.3

4.1 Location of Fixed Packages

The upgrade packages can be found on Caldera's FTP site at:

ftp://ftp.calderasystems.com/pub/updates/OpenLinux/2.3/current/RPMS/

The corresponding source code package can be found at:

ftp://ftp.calderasystems.com/pub/updates/OpenLinux/2.3/current/SRPMS

4.2 Verification

9dc46298c12e4ce5878c449477c8eaaf RPMS/glibc-2.1.3-6OL.i386.rpm
314e8df8a22a8a91ebcec87458256631 RPMS/glibc-devel-2.1.3-6OL.i386.rpm
1abc6e241431080fd8518537c2bfe05c RPMS/glibc-devel-static-2.1.3-6OL.i386.rpm
0417ac3f91cdb70844cdcfccfa002df2 RPMS/glibc-localedata-2.1.3-6OL.i386.rpm
a20d073239a2954eae0e309b904ddf8b SRPMS/glibc-2.1.3-6OL.src.rpm
4.3 Installing Fixed Packages

Upgrade the affected packages with the following commands:

rpm -Fhv glibc-*i386.rpm

5. OpenLinux eServer 2.3.1 and OpenLinux eBuilder for ECential 3.0

5.1 Location of Fixed Packages

The upgrade packages can be found on Caldera's FTP site at:

ftp://ftp.calderasystems.com/pub/updates/eServer/2.3/current/RPMS/

The corresponding source code package can be found at:

ftp://ftp.calderasystems.com/pub/updates/eServer/2.3/current/SRPMS

5.2 Verification

d39b9c6ac5ac1df9e80697378523c5f6 RPMS/glibc-2.1.3-6S.i386.rpm
e7b5b186cf417d85019cdc8ae4ecd5b7 RPMS/glibc-devel-2.1.3-6S.i386.rpm
a27c78c47fa17828371af34acafc3116 RPMS/glibc-devel-static-2.1.3-6S.i386.rpm
02119c37b969a3542902d71c6928509d RPMS/glibc-localedata-2.1.3-6S.i386.rpm
b73f5ccb9f77285ee015f04b03d3aeed SRPMS/glibc-2.1.3-6S.src.rpm
5.3 Installing Fixed Packages

Upgrade the affected packages with the following commands:

rpm -Fvh glibc-*i386.rpm

6. OpenLinux eDesktop 2.4

6.1 Location of Fixed Packages

The upgrade packages can be found on Caldera's FTP site at:

ftp://ftp.calderasystems.com/pub/updates/eDesktop/2.4/current/RPMS/

The corresponding source code package can be found at:

ftp://ftp.calderasystems.com/pub/updates/eDesktop/2.4/current/SRPMS

6.2 Verification

a858ce863ee8dccaadb68e5be00a9d20 RPMS/glibc-2.1.3-6.i386.rpm
e92757ff035c8d951667f10b710fa176 RPMS/glibc-devel-2.1.3-6.i386.rpm
deb77710633dfc7adc464eef059c7b09 RPMS/glibc-devel-static-2.1.3-6.i386.rpm
2595931b57b6d7023cfdf8216eb33deb RPMS/glibc-localedata-2.1.3-6.i386.rpm
050f35604750f406d952bca68ceb128e SRPMS/glibc-2.1.3-6.src.rpm
6.3 Installing Fixed Packages

Upgrade the affected packages with the following commands:

rpm -Fvh glibc-*i386.rpm

7. References

This and other Caldera security resources are located at:

http://www.calderasystems.com/support/security/index.html

This security fix closes Caldera's internal Problem Report 8730.

8. Disclaimer

Caldera Systems, Inc. is not responsible for the misuse of any of the information we provide on this website and/or through our security advisories. Our advisories are a service to our customers intended to promote secure installation and use of Caldera OpenLinux.

9. Acknowledgements

Caldera Systems, Inc. wishes to thank the people at Wirex, and Solar Designer, for their input.