Hardening the Oracle HTTP Server, part 1

The Oracle HTTP Server (OHS) is a version of the Apache HTTP daemon, modified by Oracle to work with it’s Application Server suite. The Application Server suite is called ‘Fusion Middleware’ with version 11. The OHS acts/can act as a frontend to application servers like OC4J and Weblogic. In my opinion an application server should always have an http server in front of it, to act as:
– Logger
– SSL offloader
– Firewall
In my opinion it would also be very good to let the OHS be a frontend for APEX.

The OHS is only a decent firewall if you made sure it can only do what you have intended it to do. Sadly, this isn’t the case by default. Whilst the most recent (11.1) version is quite safe (stripped of functionality), it only is because it’s better than its predecessors, which where quite ‘open’.

Hardening is essentially done the same way as firewalling is: disable everything (disable all functionality) and enable only the needed functionality as limited as possible.

A decent way of checking enabled functionality, is using Nikto 2. Nikto is a web server scanner.

Here is an example:

$ ./nikto.pl -host example.com
- Nikto v2.1.1
---------------------------------------------------------------------------
+ Target IP: xxx.xxx.xxx.xxx
+ Target Hostname: example.com
+ Target Port: 80
+ Start Time: 2010-05-26 10:33:35
---------------------------------------------------------------------------
+ Server: Oracle-Application-Server-10g/10.1.2.0.2 Oracle-HTTP-Server OracleAS-Web-Cache-10g/10.1.2.0.2 (G;max-age=0+0;age=0;ecid=201564454590,0)
+ Uncommon header 'tcn' found, with contents: choice
+ ETag header found on server, inode: 3425418, size: 20042, mtime: 0x43e7685d;493cf3fe
+ Number of sections in the version string differ from those in the database, the server reports: oracle-application-server-10g/10.1.2.0.2oracle-http-serveroracleas-web-cache-10g/10.1.2.0.2(g;max-age=0+0;age=0;ecid=201564454590,0) while the database has: 10.1.3.1.0. This may cause false positives.
+ Oracle-Application-Server-10g/10.1.2.0.2Oracle-HTTP-ServerOracleAS-Web-Cache-10g/10.1.2.0.2(G;max-age=0+0;age=0;ecid=201564454590,0) appears to be outdated (current is at least 10.1.3.1.0)
+ Allowed HTTP Methods: GET, HEAD, OPTIONS, TRACE, POST, PUT, DELETE, CONNECT, PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK
+ OSVDB-397: HTTP method ('Allow' Header): 'PUT' method could allow clients to save files on the web server.
+ OSVDB-5646: HTTP method ('Allow' Header): 'DELETE' may allow clients to remove files on the web server.
+ HTTP method ('Allow' Header): 'CONNECT' may allow server to proxy client requests.
+ HTTP method ('Allow' Header): 'PROPFIND' may indicate DAV/WebDAV is installed. This may be used to get directory listings if indexing is allow but a default page exists.
+ HTTP method ('Allow' Header): 'PROPPATCH' indicates WebDAV is installed.
+ OSVDB-5647: HTTP method ('Allow' Header): 'MOVE' may allow clients to change file locations on the web server.
+ OSVDB-877: HTTP TRACE method is active, suggesting the host is vulnerable to XST
+ OSVDB-27487: Apache is vulnerable to XSS via the Expect header
+ OSVDB-700: /fcgi-bin/echo?foo=alert('Vulnerable'): Fast-CGI has two default CGI programs (echo.exe/echo2.exe) vulnerable to Cross Site Scripting (XSS). http://www.cert.org/advisories/CA-2000-02.html.
+ OSVDB-3954: /fcgi-bin/echo2?foo=alert('Vulnerable'): Fast-CGI has two default CGI programs (echo.exe/echo2.exe) vulnerable to Cross Site Scripting (XSS). http://www.cert.org/advisories/CA-2000-02.html.
+ OSVDB-561: /server-status: This reveals Apache information. Comment out appropriate line in httpd.conf or restrict access to allowed hosts.
+ OSVDB-3233: /index.html.de: Apache default foreign language file found. All default files should be removed from the web server as they may give an attacker additional system information.
+ OSVDB-3233: /index.html.en: Apache default foreign language file found. All default files should be removed from the web server as they may give an attacker additional system information.
+ OSVDB-3233: /index.html.es: Apache default foreign language file found. All default files should be removed from the web server as they may give an attacker additional system information.
+ OSVDB-3233: /index.html.fr: Apache default foreign language file found. All default files should be removed from the web server as they may give an attacker additional system information.
+ OSVDB-3233: /index.html.it: Apache default foreign language file found. All default files should be removed from the web server as they may give an attacker additional system information.
+ OSVDB-3092: /fcgi-bin/echo: The FastCGI echo program may reveal system info or lead to other attacks.
+ OSVDB-3092: /fcgi-bin/echo2: The FastCGI echo2 program may reveal system info or lead to other attacks.
+ OSVDB-3233: /j2ee/: j2ee directory found--possibly an Oracle app server directory.
+ OSVDB-3233: /icons/README: Apache default file found.
+ 3823 items checked: 25 item(s) reported on remote host
+ End Time: 2010-05-26 10:44:18 (643 seconds)
---------------------------------------------------------------------------
+ 1 host(s) tested


There are all kinds of things to see here (some highlights):
-The server describes into detail what software is used. Not a problem on itself, but it gives very much information which can perfectly be used to attack the server, or which can be used to determine if the server is vulnerable:

+ Server: Oracle-Application-Server-10g/10.1.2.0.2 Oracle-HTTP-Server OracleAS-Web-Cache-10g/10.1.2.0.2

-Nikto tells there are newer versions of the OHS:

+ Oracle-Application-Server-10g/10.1.2.0.2Oracle-HTTP-ServerOracleAS-Web-Cache-10g/10.1.2.0.2(G;max-age=0+0;age=0;ecid=201564454590,0) appears to be outdated (current is at least 10.1.3.1.0)

-Nikto has determined this host is vulnerable to Cross Site Scripting (XSS):

+ OSVDB-27487: Apache is vulnerable to XSS via the Expect header

-Nikto found some files which gives away even more detailed information:

+ OSVDB-3092: /fcgi-bin/echo: The FastCGI echo program may reveal system info or lead to other attacks.

This is very much and detailed information about the configuration of this server.

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• apache
• apex
• harden
• hardening
• httpd
• OAS
• oc4j
• ohs
• security
• weblogic