USN-72-1: Perl vulnerabilities

2 February 2005

perl vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 4.10

Software Description


Two exploitable vulnerabilities involving setuid-enabled perl scripts have been discovered. The package “perl-suid” provides a wrapper around perl which allows to use setuid-root perl scripts, i.e. user-callable Perl scripts which have full root privileges.

Previous versions allowed users to overwrite arbitrary files by setting the PERLIO_DEBUG environment variable and calling an arbitrary setuid-root perl script. The file that PERLIO_DEBUG points to was then overwritten by Perl debug messages. This did not allow precise control over the file content, but could destroy important data. PERLIO_DEBUG is now ignored for setuid scripts. (CAN-2005-0155)

In addition, calling a setuid-root perl script with a very long path caused a buffer overflow if PERLIO_DEBUG was set. This buffer overflow could be exploited to execute arbitrary files with full root privileges. (CAN-2005-0156)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 4.10

To update your system, please follow these instructions: