Describe CVE-2011-4451.
What is CVE-2011-4451?
libs/Wakka.class.php in WikkaWiki 1.3.1 and 1.3.2, when the spam_logging option is enabled, allows remote attackers to write arbitrary PHP code to the spamlog_path file via the User-Agent HTTP header in an addcomment request.  NOTE: the vendor disputes this issue because the rendering of the spamlog_path file never uses the PHP interpreter.