bzip2 compressed files could inherit the permissions of a symbolic link

bzip2-compression-symlink (9128) The risk level is classified as MediumMedium Risk


bzip2 could allow a file to inherit the permissions of a symbolically linked file when the file is compressed. This would cause the file to potentially have insecure permissions when decompressed.


Obtain Information


Upgrade to the latest version of bzip2 (1.0.2 or later), available from the bzip2 Web page. See References.

For FreeBSD:
Apply the patch for this vulnerability, as listed in FreeBSD Security Advisory FreeBSD-SA-02:25. See References.

For CalderaOpenLinux Server and Workstation 3.1 and 3.1.1:
Upgrade to the latest bzip2 package (1.0.0-7MR or later) as listed in SCO Security Advisory CSSA-2002-039.0. See References.

For other distributions:
Contact your vendor for upgrade or patch information.


  • bzip2 Web site: The bzip2 and libbzip2 official home page.
  • FreeBSD Security Advisory FreeBSD-SA-02:25: bzip2 contains multiple security vulnerabilities.
  • SCO Security Advisory CSSA-2002-039.0: Linux: bzip2 file creation and symbolic link vulnerabilities.
  • BID-4776: bzip2 Archive Inherited Symbolic Link Permissions Vulnerability
  • CVE-2002-0761: bzip2 before 1.0.2 in FreeBSD 4.5 and earlier, OpenLinux 3.1 and 3.1.1, and possibly systems, uses the permissions of symbolic links instead of the actual files when creating an archive, which could cause the files to be extracted with less restrictive permissions than intended.
  • OSVDB ID: 5115: bzip2 Symbolic Link Permission Inheritance

Platforms Affected:

  • FreeBSD FreeBSD 4.4
  • FreeBSD FreeBSD 4.5
  • Julian Seward bzip2 1.0.1 and prior
  • SCO Caldera OpenLinux Server 3.1
  • SCO Caldera OpenLinux Server 3.1.1
  • SCO Caldera OpenLinux Workstation 3.1
  • SCO Caldera OpenLinux Workstation 3.1.1


May 20, 2002

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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