Cross-site request forgery (CSRF) vulnerability in phpBB 2.0.19, when Link to off-site Avatar or bbcode (IMG) are enabled, allows remote attackers to perform unauthorized actions as a logged in user via a link or IMG tag in a user profile, as demonstrated using links to (1) admin/admin_users.php and (2) modcp.php.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24497
http://www.vupen.com/english/advisories/2006/0445
http://securityreason.com/securityalert/406
http://secunia.com/advisories/18693
http://lists.grok.org.uk/pipermail/full-disclosure/2006-February/041920.html