The remote host is missing an update to squid announced via advisory DSA 474-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20474-1

A vulnerability was discovered in squid, an Internet object cache, whereby access control lists based on URLs could be bypassed (CVE-2004-0189). Two other bugs were also fixed with patches squid-2.4.STABLE7-url_escape.patch (a buffer overrun which does not appear to be exploitable) and squid-2.4.STABLE7-url_port.patch (a potential denial of service). For the stable distribution (woody) these problems have been fixed in version 2.4.6-2woody2. For the unstable distribution (sid) these problems have been fixed in version 2.5.5-1. We recommend that you update your squid package.