Multiple cross-site scripting (XSS) vulnerabilities in GuppY 4.5.3a and earlier allow remote attackers to inject arbitrary web script or HTML via (1) the pg parameter to printfaq.php, or the (2) Referer or (3) User-Agent HTTP headers, which are not properly handled by error.php.

Direct static code injection vulnerability in error.php in GuppY 4.5.9 and earlier, when register_globals is disabled, allows remote attackers to execute arbitrary PHP code via the _SERVER[REMOTE_ADDR] parameter, which is injected into a .inc script that is later included by the main script.

Multiple directory traversal vulnerabilities in GuppY 4.5.9 and earlier allow remote attackers to read and include arbitrary files via (1) the meskin parameter to admin/editorTypetool.php, or the lng parameter to the in admin/inc scripts (2) archbatch.php, (3) dbbatch.php, and (4) nwlmail.php.

Directory traversal vulnerability in dwnld.php in GuppY 4.5.11 allows remote attackers to overwrite arbitrary files via a "%2E." (mixed encoding) in the pg parameter.

Multiple cross-site scripting (XSS) vulnerabilities in GuppY before 4.6.28 allow remote attackers to inject arbitrary web script or HTML via the (1) "an" parameter to agenda.php or (2) cat parameter to mobile/thread.php.