The remote Debian host is missing a security-related update.
Several vulnerabilities have been found in the Apache HTTPD server. - CVE-2012-3499 The modules mod_info, mod_status, mod_imagemap, mod_ldap, and mod_proxy_ftp did not properly escape hostnames and URIs in HTML output, causing cross site scripting vulnerabilities. - CVE-2012-4558 Mod_proxy_balancer did not properly escape hostnames and URIs in its balancer-manager interface, causing a cross site scripting vulnerability. - CVE-2013-1048 Hayawardh Vijayakumar noticed that the apache2ctl script created the lock directory in an unsafe manner, allowing a local attacker to gain elevated privileges via a symlink attack. This is a Debian specific issue.
Upgrade the apache2 packages. For the stable distribution (squeeze), these problems have been fixed in version 2.2.16-6+squeeze11.