PHP-Nuke 5.x allows remote attackers to perform arbitrary SQL operations by modifying the "prefix" variable when calling any scripts that do not already define the prefix variable (e.g., by including mainfile.php), such as article.php.

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.

PHP-Nuke 7.3, and other products that use the PHP-Nuke codebase such as the Nuke Cops betaNC PHP-Nuke Bundle, OSCNukeLite 3.1, and OSC2Nuke 7x do not properly use the eregi() PHP function with $SERVER['PHPSELF'] to identify the calling script, which allows remote attackers to directly access scripts, obtain path information via a PHP error message, and possibly gain access, as demonstrated using an HTTP request that contains the "admin.php" string.

SQL injection vulnerability in PHP-Nuke 6.9 and earlier, and possibly 7.x, allows remote attackers to inject arbitrary SQL code and gain sensitive information via (1) the category variable in the Search module or (2) the admin variable in the WebLinks module.

Cross-site request forgery (CSRF) vulnerability in admin.php in Francisco Burzi PHP-Nuke allows remote attackers to add administrative accounts via an AddAuthor action with modified addname and addradminsuper parameters.

sqllayer.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 sqldebug parameter to (1) index.php and (2) 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.

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 the YourAccount module for PHP-Nuke 5.0 through 6.0 allows remote attackers to inject arbitrary web script or HTML via the useravatar parameter.

Multiple SQL injection vulnerabilities in the WebLinks module for PHP-Nuke 5.x through 6.5 allows remote attackers to steal sensitive information via numeric fields, as demonstrated using (1) the viewlink function and cid parameter, or (2) index.php.