The is_this_legal function in mod_dontdothat for Apache Subversion 1.4.0 through 1.7.13 and 1.8.0 through 1.8.4 allows remote attackers to bypass intended access restrictions and possibly cause a denial of service (resource consumption) via a relative URL in a REPORT request.
http://subversion.apache.org/security/CVE-2013-4505-advisory.txt
http://secunia.com/advisories/55855
http://lists.opensuse.org/opensuse-updates/2013-12/msg00048.html
http://lists.opensuse.org/opensuse-updates/2013-12/msg00029.html