The remote host is missing an update to glibc announced via advisory DSA 2122-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202122-1

Ben Hawkes and Tavis Ormandy discovered that the dynamic loader in GNU libc allows local users to gain root privileges using a crafted LD_AUDIT environment variable. For the stable distribution (lenny), this problem has been fixed in version 2.7-18lenny6. For the upcoming stable distribution (squeeze), this problem has been fixed in version 2.11.2-6+squeeze1 of the eglibc package. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your glibc packages.