The remote host is missing an update to webcalendar announced via advisory DSA 799-1. A trivially-exploitable bug was discovered in webcalendar that allows an attacker to execute arbitrary code with the privileges of the HTTP daemon on a system running a vulnerable version. The old stable distribution (woody) does not contain the webcalendar package.

For the stable distribution (sarge) this problem has been fixed in version 0.9.45-4sarge2. For the unstable distribution (sid) this problem will be fixed shortly. We recommend that you upgrade your webcalendar package immediately. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20799-1