Winn Guestbook Cross-Site Scripting and Cross-Site Request Forgery Vulnerabilities
Description
Multiple vulnerabilities have been discovered in Winn Guestbook, which can be exploited by malicious people to conduct cross-site scripting and cross-site request forgery attacks.
1) Input appended to the URL after index.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in the context of an affected site.
2) Input passed via the "name" and "email" parameters to index.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.
3) The application allows users to perform certain actions via HTTP requests without performing any validity checks to verify the requests. This can be exploited to e.g. delete guestbook entries by tricking a logged in administrator into visiting a malicious web site.
The vulnerabilities are reported in version 2.4.8d and confirmed in version 2.4.8c. Other versions may also be affected.
Vulnerable Products
Vulnerable Software: Winn Guestbook 2.x
Solution
Edit the source code to ensure that input is properly sanitised. Do not browse untrusted sites or follow untrusted links while being logged-in to the application.