CVE-2010-4407

Vulnerability

AlGuest 1.1c-patched contains multiple cross-site scripting (XSS) vulnerabilities in index.php. The nome (nickname), messaggio (message), and link (homepage) parameters are not sanitized before being rendered, allowing arbitrary HTML and JavaScript injection. The vulnerable software is available from SourceForge, and the issue is classified as unpatched as of the disclosure date [1].

Exploitation

An attacker can inject malicious script into any of the three unsanitized fields (nickname, message, homepage). No authentication is required; the attacker simply submits a guestbook entry containing the XSS payload. When other users view the guestbook page, the injected script executes in their browser. The provided proof-of-concept confirms injection via ` in the nickname and message fields and javascript:` in the homepage field [1].

Impact

Successful exploitation allows arbitrary script execution in the context of the victim’s browser. This can lead to session hijacking, defacement, or redirection to malicious sites. The impact is limited by browser security policies, but the attacker does not need elevated privileges [1].

Mitigation

As of the publication date, no patch or official update exists. The developer was notified but did not respond, and the vendor status is listed as not available. Users should consider disabling the guestbook functionality or removing the application until a fix is released [1].