The remote host is missing an update to squirrelmail announced via advisory DSA 662-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20662-1

Several vulnerabilities have been discovered in Squirrelmail, a commonly used webmail system. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2005-0104 Upstream developers noticed that an unsanitised variable could lead to cross site scripting. CVE-2005-0152 Grant Hollingworth discovered that under certain circumstances URL manipulation could lead to the execution of arbitrary code with the privileges of www-data. This problem only exists in version 1.2.6 of Squirrelmail. For the stable distribution (woody) these problems have been fixed in version 1.2.6-2. For the unstable distribution (sid) the problem that affects unstable has been fixed in version 1.4.4-1. We recommend that you upgrade your squirrelmail package.