Cross-site scripting (XSS) vulnerability in the remote RSS sidebar plugin (serendipity_plugin_remoterss) in S9Y Serendipity before 1.2.1 allows remote attackers to inject arbitrary web script or HTML via a link in an RSS feed.
https://exchange.xforce.ibmcloud.com/vulnerabilities/38947
http://www.vupen.com/english/advisories/2007/4171
http://www.securityfocus.com/bid/26783
http://www.securityfocus.com/archive/1/484800/100/0/threaded
http://www.debian.org/security/2008/dsa-1528
http://securityreason.com/securityalert/3437
http://secunia.com/advisories/29502
http://secunia.com/advisories/28012
http://blog.s9y.org/archives/187-Serendipity-1.2.1-released.html