Best Practical Solutions RT 3.8.0 through 3.8.9 and 4.0.0rc through 4.0.0rc7, when the CustomFieldValuesSources (aka external custom field) option is enabled, allows remote authenticated users to execute arbitrary code via unspecified vectors, as demonstrated by a cross-site request forgery (CSRF) attack.
https://exchange.xforce.ibmcloud.com/vulnerabilities/66791
https://bugzilla.redhat.com/show_bug.cgi?id=696795
http://www.vupen.com/english/advisories/2011/1071
http://www.securityfocus.com/bid/47383
http://www.debian.org/security/2011/dsa-2220
http://secunia.com/advisories/44189
http://lists.bestpractical.com/pipermail/rt-announce/2011-April/000188.html
http://lists.bestpractical.com/pipermail/rt-announce/2011-April/000187.html
http://blog.bestpractical.com/2011/04/security-vulnerabilities-in-rt.html