The remote host is missing an update to aircrack-ng announced via advisory DSA 1280-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201280-1

It was discovered that aircrack-ng, a WEP/WPA security analysis tool, performs insufficient validation of 802.11 authentication packets, which allows the execution of arbitrary code. The oldstable distribution (sarge) doesn't contain aircrack-ng packages. For the stable distribution (etch) this problem has been fixed in version 0.6.2-7etch1. For the unstable distribution (sid) this problem has been fixed in version 0.7-3. We recommend that you upgrade your aircrack-ng packages. Packages for