The remote host is missing an update to phpgroupware announced via advisory DSA 746-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20746-1

A vulnerability had been identified in the xmlrpc library included with phpgroupware, a web-based application including email, calendar and other groupware functionality. This vulnerability could lead to the execution of arbitrary commands on the server running phpgroupware. The security team is continuing to investigate the version of phpgroupware included with the old stable distribution (sarge). At this time we recommend disabling phpgroupware or upgrading to the current stable distribution (sarge). For the current stable distribution (sarge) this problem has been fixed in version 0.9.16.005-3.sarge0. For the unstable distribution (sid) this problem has been fixed in version 0.9.16.006-1. We recommend that you upgrade your phpgroupware package.