Rule: -- Sid: 119-8 -- Summary: This event is generated when the pre-processor http_inspect detects network traffic that may constitute an attack. -- Impact: Unknown. This may be an attempt to evade an IDS. -- Detailed Information: This event is generated when the pre-processor http_inspect detects web requests that incorporate multiple concurrent "/" characters. This may be an attempt to obfuscate an attack and may also indicate an attempt to evade an IDS. -- Affected Systems: All web servers. -- Attack Scenarios: An attacker can add multiple "/" characters to a request like this. GET http://www.victim.com////////////////vulnerable/application.dll -- 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. -- 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 --
