CVS is a version control system frequently used to manage source code
repositories. During an audit of the CVS sources, Stefan Esser
discovered an exploitable double-free bug in the CVS server.
On servers which are configured to allow anonymous read-only access, this
bug could be used by anonymous users to gain write privileges. Users with
CVS write privileges can then use the Update-prog and Checkin-prog features
to execute arbitrary commands on the server.
All users of CVS are advised to upgrade to erratum packages which contain
patches to correct the double-free bug.
