The remote host is missing an update to bzip2 announced via advisory DSA 730-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20730-1

Imran Ghory discovered a race condition in bzip2, a high-quality block-sorting file compressor and decompressor. When decompressing a file in a directory an attacker has access to, bunzip2 could be tricked to set the file permissions to a different file the user has permissions to. For the stable distribution (woody) this problem has been fixed in version 1.0.2-1.woody2 For the testing distribution (sarge) this problem has been fixed in version 1.0.2-6. For the unstable distribution (sid) this problem has been fixed in version 1.0.2-6. We recommend that you upgrade your bzip2 packages.