The remote host is missing an update to apache2 announced via advisory DSA 2405-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202405-1

Several vulnerabilities have been found in the Apache HTTPD Server: CVE-2011-3607: An integer overflow in ap_pregsub() could allow local attackers to execute arbitrary code at elevated privileges via crafted .htaccess files. CVE-2011-3368 CVE-2011-3639 CVE-2011-4317: The Apache HTTP Server did not properly validate the request URI for proxied requests. In certain reverse proxy configurations using the ProxyPassMatch directive or using the RewriteRule directive with the [P] flag, a remote attacker could make the proxy connect to an arbitrary server. The could allow the attacker to access internal servers that are not otherwise accessible from the outside. The three CVE ids denote slightly different variants of the same issue. Note that, even with this issue fixed, it is the responsibility of the administrator to ensure that the regular expression replacement pattern for the target URI does not allow a client to append arbitrary strings to the host or port parts of the target URI. For example, the configuration ProxyPassMatch ^/mail(.*) http://internal-host$1 is still insecure and should be replaced by one of the following configurations: ProxyPassMatch ^/mail(/.*) http://internal-host$1 ProxyPassMatch ^/mail/(.*) http://internal-host/$1 CVE-2012-0031: An apache2 child process could cause the parent process to crash during shutdown. This is a violation of the privilege separation between the apache2 processes and could potentially be used to worsen the impact of other vulnerabilities. CVE-2012-0053: The response message for error code 400 (bad request) could be used to expose httpOnly cookies. This could allow a remote attacker using cross site scripting to steal authentication cookies. For the oldstable distribution (lenny), these problems have been fixed in version apache2 2.2.9-10+lenny12. For the stable distribution (squeeze), these problems have been fixed in version apache2 2.2.16-6+squeeze6 For the testing distribution (wheezy), these problems will be fixed in version 2.2.22-1. For the unstable distribution (sid), these problems have been fixed in version 2.2.22-1. We recommend that you upgrade your apache2 packages.