The remote host is missing an update to newt announced via advisory DSA 1894-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201894-1

Miroslav Lichvar discovered that newt, a windowing toolkit, is prone to a buffer overflow in the content processing code, which can lead to the execution of arbitrary code. For the stable distribution (lenny), this problem has been fixed in version 0.52.2-11.3+lenny1. For the oldstable distribution (etch), this problem has been fixed in version 0.52.2-10+etch1. For the testing distribution (squeeze) and the unstable distribution (sid), this problem will be fixed soon We recommend that you upgrade your newt packages.