The remote host is missing an update to mailman announced via advisory DSA 674-3.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20674-3

Due to an incompatibility between Python 1.5 and 2.1 the last mailman update did not run with Python 1.5 anymore. This problem is corrected with this update. This advisory only updates the packages updated with DSA 674-2. The version in unstable is not affected since it is not supposed to work with Python 1.5 anymore. For completeness below is the original advisory text: Two security related problems have been discovered in mailman, web-based GNU mailing list manager. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2004-1177 Florian Weimer discovered a cross-site scripting vulnerability in mailman's automatically generated error messages. An attacker could craft an URL containing JavaScript (or other content embedded into HTML) which triggered a mailman error page that would include the malicious code verbatim. CVE-2005-0202 Several listmasters have noticed unauthorised access to archives of private lists and the list configuration itself, including the users passwords. Administrators are advised to check the webserver logfiles for requests that contain /...../ and the path to the archives or cofiguration. This does only seem to affect installations running on web servers that do not strip slashes, such as Apache 1.3. For the stable distribution (woody) these problems have been fixed in version 2.0.11-1woody11. We recommend that you upgrade your mailman package.