Bypassing WAFs with the phantom $Version cookie
Summary
This article explores parser discrepancy vulnerabilities in HTTP cookies, specifically focusing on how the '$Version' cookie can be manipulated to bypass Web Application Firewalls (WAFs). The author details a technique using a phantom '$Version' cookie to exploit these discrepancies for security circumvention.
IFF Assessment
FOE
This article details a method for bypassing security controls, which is detrimental to defenders.
Defender Context
Defenders need to be aware of how WAFs might be susceptible to cookie manipulation, especially those that rely on strict parsing of HTTP headers. This research highlights a potential blind spot that attackers could exploit to deliver malicious payloads or gain unauthorized access.