TWiki: Arbitrary command execution

Background

TWiki is a Web-based groupware tool based around the concept of wiki pages that can be edited by anybody with a Web browser.

Description

The TWiki search function, which uses a shell command executed via the Perl backtick operator, does not properly escape shell metacharacters in the user-provided search string.

Impact

An attacker can insert malicious commands into a search request, allowing the execution of arbitrary commands with the privileges of the user running TWiki (usually the Web server user).

Workaround

There is no known workaround at this time.

Resolution

All TWiki users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=www-apps/twiki-20040902"