Texinfo: Insecure temporary file creation

Background

Texinfo is the official documentation system created by the GNU project.

Description

Frank Lichtenheld has discovered that the “sort_offline()” function in texindex insecurely creates temporary files with predictable filenames.

Impact

A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When texindex is executed, this would result in the file being overwritten with the rights of the user running the application.

Workaround

There is no known workaround at this time.

Resolution

All Texinfo users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-apps/texinfo-4.8-r1"