The remote host is missing an update to gcc-3.4 announced via advisory DSA 1170-1. Jürgen Weigert discovered that upon unpacking JAR archives fastjar from the GNU Compiler Collection does not check the path for included files and allows to create or overwrite files in upper directories.
For the stable distribution (sarge) this problem has been fixed in version 3.4.3-13sarge1. For the unstable distribution (sid) this problem has been fixed in version 4.1.1-11. We recommend that you upgrade your fastjar package. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201170-1