Subversion is a concurrent version control system which enables one or more users to collaborate in developing and maintaining a hierarchy of files and directories while keeping a history of all changes. The mod_dav_svn module is used with the Apache HTTP Server to allow access to Subversion repositories via HTTP. A NULL pointer dereference flaw was found in the way the mod_dav_svn module processed certain requests to lock working copy paths in a repository. A remote attacker could issue a lock request that could cause the httpd process serving the request to crash. Red Hat would like to thank Hyrum Wright of the Apache Subversion project for reporting this issue. Upstream acknowledges Philip Martin, WANdisco, Inc. as the original reporter. All Subversion users should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing the updated packages, you must restart the httpd daemon, if you are using mod_dav_svn, for the update to take effect.