The remote host is missing an update to prozilla announced via advisory DSA 719-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20719-1

Several format string problems have been discovered in prozilla, a multi-threaded download accelerator, that can be exploited by a malicious server to execute arbitrary code with the rights of the user running prozilla. For the stable distribution (woody) these problems have been fixed in version 1.3.6-3woody2. For the unstable distribution (sid) these problems have been fixed in version 1.3.7.4-1. We recommend that you upgrade your prozilla package.