The remote host is missing an update to glibc announced via advisory DSA 2122-2.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202122-2

Colin Watson discovered that the update for stable relased in DSA-2122-1 did not complete address the underlying security issue in all possible scenarios. For the stable distribution (lenny), this problem has been fixed in version 2.7-18lenny7. For the testing distribution (squeeze) and the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your glibc packages.