The remote host is missing an update to squid announced via advisory DSA 1646-2.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201646-2

In DSA 1646-1, an update was announced for a denial of service vulnerability in squid, a caching proxy server. Due to an error in packaging and in testing, the updated packages did not correct the weakness. An updated release is available which corrects the error. For reference, the original advisory text follows. A weakness has been discovered in squid, a caching proxy server. The flaw was introduced upstream in response to CVE-2007-6239, and announced by Debian in DSA-1482-1. The flaw involves an over-aggressive bounds check on an array resize, and could be exploited by an authorized client to induce a denial of service condition against squid. For the stable distribution (etch), these problems have been fixed in version 2.6.5-6etch4. We recommend that you upgrade your squid packages.