The remote host is missing updates announced in advisory RHSA-2009:1490. SquirrelMail is a standards-based webmail package written in PHP. Form submissions in SquirrelMail did not implement protection against Cross-Site Request Forgery (CSRF) attacks. If a remote attacker tricked a user into visiting a malicious web page, the attacker could hijack that user's authentication, inject malicious content into that user's preferences, or possibly send mail without that user's permission. (CVE-2009-2964) Users of SquirrelMail should upgrade to this updated package, which contains a backported patch to correct these issues.
Please note that this update is available via Red Hat Network. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date