Rule: 

--
Sid: 
119-15

-- 
Summary: 
This event is generated when the pre-processor http_inspect detects network traffic that may constitute an attack.

-- 
Impact: 
Unknown. This may indicate an attempt to evade an IDS or an attack on a web server.

--
Detailed Information:
This event is generated when the http_inspect pre-processor detects a request for a URL that is longer than a specified length. This may indicate an attack or an attempt to evade an IDS.

Lotus Domino Server Web servers are reported prone to a Denial of Service condition when a long request is made to the server using unicode characters. The http_inspect pre-processor will generate this event should a Domino server be attacked in this way.

Specifically, when a request is made to /cgi-bin/ with approximately 330 unicode characters appended to the URL, the webserver will crash and a DoS condition will be evident.

Stack-based buffer overflow in the map_uri_to_worker function (native/common/jk_uri_worker_map.c) in mod_jk.so for Apache Tomcat JK Web Server Connector 1.2.19 and 1.2.20, as used in Tomcat 4.1.34 and 5.5.20, allows remote attackers to execute arbitrary code via a long URL that triggers the overflow in a URI worker map routine.  

The maximum expected length of the URL is user configured.

This event can be controlled using the ((http_inspect)) configuration options.

--
Affected Systems:
All web servers
Lotus Domino 6.5.1 and 6.0.3

--
Attack Scenarios: 
An attacker may supply an over-long URI in an attempt to evade an IDS or in a possible attack against a web server.

-- 
Ease of Attack: 
Simple.

-- 
False Positives:
None Known.

--
False Negatives:
None Known.

-- 

Corrective Action:
Check the target host for signs of compromise.

Apply any appropriate vendor supplied patches.

Upgrade to the latest non-affected version of the software.

--
Contributors:
Daniel Roelker <droelker@sourcefire.com> 
Sourcefire Vulnerability Research Team
Nigel Houghton <nigel.houghton@sourcefire.com>

-- 
Additional References:

HTTP IDS Evasions Revisited - Daniel Roelker
http://docs.idsresearch.org/http_ids_evasions.pdf

iDefense:
http://www.idefense.com/application/poi/display?id=224&type=vulnerabilities

NIST:
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-0774

--
