240 Apache prior 2.0.49 HTTP response splitting HTTP 2004/09/16 Marc Ruef marc dot ruef at computec dot ch http://www.computec.ch computec.ch Marc Ruef marc dot ruef at computec dot ch http://www.computec.ch computec.ch 2004/11/14 2.0 Enhanced the solution text in version 1.1. Corrected the plugin structure and added the accuracy values in 1.2. Improved the pattern matching and introduced the plugin changelog in 2.0 tcp 80 open|send HEAD / HTTP/1.0\n\n|sleep|close|pattern_exists HTTP/1.[0-1] ### *Server: Apache/2.0.[0-3]* OR HTTP/1.[0-1] ### *Server: Apache/2.0.4[0-9]* 80 This plugin was written with the ATK Attack Editor. Amit Klein http://www.sanctuminc.com Sanctum Inc. 2004/03/04 http://www.sanctuminc.com/pdf/whitepaper_httpresponse.pdf Apache Software Foundation apache at apache dot org http://httpd.apache.org Apache2 prior 2.0.49 and many other HTTP daemons and CGI solutions are also vulnerable Apache2 newer than 2.0.49 or other web solutions Cross Site Scripting The remote host is running an Apache web server that is vulnerable to a HTTP response splitting attack. These attacks involve abusing various input validation flaws in these implementations to split HTTP responses into multiple parts in such a way that response data may be misrepresented to client users. Exploitation would occur by injecting variations of CR/LF sequences into parts of HTTP response headers that the attacker may control or influence. The general consequences of exploitation are that an attacker may misrepresent web content to the client, potentially enticing the user to trust the content and take actions based on this false trust. While the various implementations listed in the paper contribute to these attacks, this issue will most likely be exposed through web applications that do not properly account for CR/LF sequences when accepting user-supplied input that may be returned in server responses. This vulnerability could also aid in exploitation of cross-site scripting vulnerabilities. If the web server is not used it should be de-installed or de-activated. Install the newest patch or bugfix to solve the problem or upgrade to the latest software version which is not vulnerable anymore. To make it harder to find the server the daemon could be configured to listen at another port (e.g. 8081). Alternation of the application banner can confuse an attacker and let him determine the wrong software. Additionally limit unwanted connections and communications with firewalling. Approx. 2 hours Yes http://www.securityfocus.com/bid/9804/exploit/ Yes Yes Medium 7 7 6 6 9804 Hacking Exposed: Network Security Secrets & Solutions, Stuart McClure, Joel Scambray and George Kurtz, February 25, 2003, 4th Edition, McGraw-Hill Osborne Media, ISBN 0072227427 http://www.securityfocus.com/advisories/7053