steps/utils/save_pref.inc in Roundcube webmail before 0.8.7 and 0.9.x before 0.9.5 allows remote attackers to modify configuration settings via the _session parameter, which can be leveraged to read arbitrary files, conduct SQL injection attacks, and execute arbitrary code.
http://www.interworx.com/developers/changelog/version-5-0-13-build-574-2014-02-19
http://www.debian.org/security/2013/dsa-2787
http://trac.roundcube.net/ticket/1489382
http://roundcube.net/news/2013/10/21/security-updates-095-and-087/
http://lists.opensuse.org/opensuse-updates/2014-03/msg00035.html