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.
Multiple unrestricted file upload vulnerabilities in fileupload.php in PivotX before 2.3.9 allow remote authenticated users to execute arbitrary PHP code by uploading a file with a (1) .php or (2) .php# extension, and then accessing it via unspecified vectors.