sql_layer.php in PHP-Nuke 5.4 and earlier does not restrict access to debugging features, which allows remote attackers to gain SQL query information by setting the sql_debug parameter to (1) index.php and (2) modules.php.

SQL injection vulnerability in PHP-Nuke before 6.0 allows remote authenticated users to modify the database and gain privileges via the "bio" argument to modules.php.

index.php for PHP-Nuke 5.4 and earlier allows remote attackers to determine the physical pathname of the web server when the file parameter is set to index.php, which triggers an error message that leaks the pathname.

index.php in Francisco Burzi PHP-Nuke 5.3.1 and earlier, and possibly other versions before 5.5, allows remote attackers to execute arbitrary PHP code by specifying a URL to the malicious code in the file parameter.

Cross-site scripting (XSS) vulnerability in PHP-Nuke 5.3.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the (1) uname parameter in user.php, (2) ttitle, letter and file parameters in modules.php, (3) subject, story and storyext parameters in submit.php, (4) upload parameter in admin.php and (5) fname parameter in friend.php.

Cross-site scripting (XSS) vulnerability in im.php in IMessenger for PHP-Nuke allows remote attackers to inject arbitrary web script or HTML via a message.

PHP-Nuke 5.2 allows remote attackers to copy and delete arbitrary files by calling case.filemanager.php with admin.php as an argument, which sets the $PHP_SELF variable and makes it appear that case.filemanager.php is being called by admin.php instead of the user.

PHP-Nuke 5.1 stores user and administrator passwords in a base-64 encoded cookie, which could allow remote attackers to gain privileges by stealing or sniffing the cookie and decoding it.

Directory traversal vulnerability in modules.php in Gallery before 1.2.3 allows remote attackers to read arbitrary files via a .. (dot dot) in the include parameter.

admin.php in PHP-Nuke 5.2 and earlier, except 5.0RC1, does not check login credentials for upload operations, which allows remote attackers to copy and upload arbitrary files and read the PHP-Nuke configuration file by directly calling admin.php with an upload parameter and specifying the file to copy.