Bugzilla 2.10 allows remote attackers to execute arbitrary commands via shell metacharacters in a username that is then processed by (1) the Bugzilla_login cookie in post_bug.cgi, or (2) the who parameter in process_bug.cgi.
http://www.securityfocus.com/bid/1199
http://www.mozilla.org/projects/bugzilla/security2_12.html
http://www.atstake.com/research/advisories/2001/a043001-1.txt