The remote host is missing an update to simplesamlphp announced via advisory DSA 2330-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202330-1

Issues were found in the handling of XML encryption in simpleSAMLphp, an application for federated authentication. The following two issues have been addressed: It may be possible to use an SP as an oracle to decrypt encrypted messages sent to that SP. It may be possible to use the SP as a key oracle which can be used to forge messages from that SP by issuing 300000-2000000 queries to the SP. The oldstable distribution (lenny) does not contain simplesamlphp. For the stable distribution (squeeze), this problem has been fixed in version 1.6.3-2. The testing distribution (wheezy) will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 1.8.2-1. We recommend that you upgrade your simplesamlphp packages.