The remote host is missing an update to apache2 announced via advisory DSA 2579-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202579-1

A vulnerability has been found in the Apache HTTPD Server: CVE-2012-4557 A flaw was found when mod_proxy_ajp connects to a backend server that takes too long to respond. Given a specific configuration, a remote attacker could send certain requests, putting a backend server into an error state until the retry timeout expired. This could lead to a temporary denial of service. In addition, this update also adds a server side mitigation for the following issue: CVE-2012-4929 If using SSL/TLS data compression with HTTPS in an connection to a web browser, man-in-the-middle attackers may obtain plaintext HTTP headers. This issue is known as the CRIME attack. This update of apache2 disables SSL compression by default. A new SSLCompression directive has been backported that may be used to re-enable SSL data compression in environments where the CRIME attack is not an issue. For more information, please refer to: http://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcompression For the stable distribution (squeeze), these problems have been fixed in version 2.2.16-6+squeeze10. For the testing distribution (wheezy), these problems have been fixed in version 2.2.22-12. For the unstable distribution (sid), these problems have been fixed in version 2.2.22-12. We recommend that you upgrade your apache2 packages.