The remote host is missing an update to pwlib announced via advisory DSA 448-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20448-1

Multiple vulnerabilities were discovered in pwlib, a library used to aid in writing portable applications, whereby a remote attacker could cause a denial of service or potentially execute arbitrary code. This library is most notably used in several applications implementing the H.323 teleconferencing protocol, including the OpenH323 suite, gnomemeeting and asterisk. For the current stable distribution (woody) this problem has been fixed in version 1.2.5-5woody1. For the unstable distribution (sid), this problem will be fixed soon. Refer to Debian bug #233888 for details. We recommend that you update your pwlib package.