The remote host is missing an update to icu announced via advisory DSA 1889-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201889-1

It was discovered that the ICU unicode library performed incorrect processing of invalid multibyte sequences, resulting in potential bypass of security mechanisms. For the old stable distribution (etch), this problem has been fixed in version 3.6-2etch3. For the stable distribution (lenny), this problem has been fixed in version 3.8.1-3+lenny2. For the unstable distribution (sid), this problem has been fixed in version 4.0.1-1. We recommend that you upgrade your icu packages.