The remote host is missing an update to the system as announced in the referenced advisory.

Update your system with the appropriate patches or software upgrades. http://httpd.apache.org/security/vulnerabilities_13.html http://seclists.org/fulldisclosure/2011/Oct/232 http://www.vuxml.org/freebsd/d8c901ff-0f0f-11e1-902b-20cf30e32f6d.html

The following packages are affected: apache apache+ssl apache+ipv6 apache+mod_perl apache+mod_ssl apache+mod_ssl+ipv6 ru-apache-1.3 ru-apache+mod_ssl CVE-2011-3368 The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21 does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers via a malformed URI containing an initial @ (at sign) character.