Subversion is an advanced version control system, similar to CVS, which supports additional functionality such as the ability to move, copy and delete files and directories. A Subversion server may be run as an Apache module, a standalone server (svnserve), or on-demand over ssh (a la CVS' ":ext:" protocol). The mod_authz_svn Apache module works with Subversion in Apache to limit access to parts of Subversion repositories based on policy set by the administrator.
Users with write access to part of a Subversion repository may bypass read restrictions on any part of that repository. This can be done using an "svn copy" command to copy the portion of a repository the user wishes to read into an area where they have write access.
Since copies are versioned, any such copy attempts will be readily apparent.
This is a low-risk vulnerability. It affects only users of Subversion who are running servers inside Apache and using mod_authz_svn. Additionally, this vulnerability may be exploited only by users with write access to some portion of a repository.
Keep sensitive content separated into different Subversion repositories, or disable the Apache Subversion server and use svnserve instead.
All Subversion users should upgrade to the latest available version:
# emerge sync
# emerge -pv ">=dev-util/subversion-1.0.6"
# emerve ">=dev-util/subversion-1.0.6"