PivotX before 2.3.11 does not validate the new file extension...

Vulnerability Description

PivotX before 2.3.11 does not validate the new file extension when renaming a file with multiple extensions, which allows remote attackers to execute arbitrary code by uploading a crafted file, as demonstrated by a file named foo.php.php.

References

• http://software-talk.org/blog/2015/06/session-fixation-xss-code-execution-vulnerability-pivotx/
• http://packetstormsecurity.com/files/132474/PivotX-2.3.10-Session-Fixation-XSS-Code-Execution.html
• http://blog.pivotx.net/archive/2015/06/21/pivotx-2311-released
• http://www.securityfocus.com/bid/75577
• http://www.securityfocus.com/archive/1/535860/100/0/threaded
• http://sourceforge.net/p/pivot-weblog/code/4452/tree//branches/2.3.x/pivotx/fileupload.php?diff=51a4cb5e34309d75c0d1612a:4451