Atomicorp WAF Rule 390712

Rule Summary

• Rule ID: 390712
• Status: Active
• Alert message: Atomicorp.com WAF Rules: Attack Blocked - HTTP Response Splitting Attack
• Observed CWEs: CWE-79 (1)
• Revision: 5
• Rule severity: Alert (1)
• Phase: 2 (request body)
• Request surfaces: Request URI, Request cookies, Request argument names, JSON request data, SOAP request data
• Rule action: deny
• HTTP status: 400
• Logging: log, auditlog

Description

This rule detects possible HTTP response splitting attacks. These types of attacks work by making the server print a carriage return (CR, ASCII 0x0D) line feed (LF, ASCII 0x0A) sequence followed by content supplied by the attacker in the header section of its response, typically by including them in input fields sent to the application. Per the HTTP standard (RFC 2616), headers are separated by one CRLF and the response’s headers are separated from its body by two. Therefore, the failure to remove CRs and LFs allows the attacker to set arbitrary headers, take control of the body, or break the response into two or more separate responses—hence the name.

False Positives

It is not recommended that you disable this rule if you have a false positive. If you believe this is a false positive, please report this to our security team to determine if this is a legitimate case, or if its clever attack on your system. Instructions to report false positives are detailed on the Reporting False Positives wiki page. If it is a false positive, we will fix the issue in the rules and get a release out to you promptly.

Selected Related CVEs

This is a selected list of documented research observations, not an exhaustive coverage matrix. Absence of a CVE does not imply absence of protection.

Observed CWEs

These CWEs are recorded on published CVEs in the selected observations associated with this rule. They are observational relationships, not a claim that the rule universally blocks every vulnerability assigned to a CWE.

Documentation Source

• Original wiki page: WAF 390712
• Source revision: 5601
• Source revision date: 2015-11-20