The remote host is missing an update to mlmmj announced via advisory DSA 2073-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202073-1

Florian Streibelt reported a a directory traversal flaw in the way the Mailing List Managing Made Joyful mailing list manager processed users' requests originating from the administrator web interface without enough input validation. A remote, authenticated attacker could use these flaws to write and / or delete arbitrary files. For the stable distribution (lenny), these problems have been fixed in version 1.2.15-1.1+lenny1. For the unstable distribution (sid), these problems have been fixed in version 1.2.17-1.1. We recommend that you upgrade your mlmmj package.