The Most Overlooked Vulnerability — Http request Smuggling
This title could be clearer and more informative.Try out Clickbait Shieldfor free (5 uses left this month).
HTTP Request Smuggling exploits ambiguity in how front-end and back-end servers parse HTTP/1.1 request boundaries using Content-Length and Transfer-Encoding headers. When these servers rely on different headers to determine where a request ends, an attacker can inject a smuggled request into the connection pipeline. The three main variants are CL.TE, TE.CL, and TE.TE. Real-world impacts include WAF bypass, session hijacking, cache poisoning, and access to internal endpoints. Mitigations include rejecting requests with both headers, normalizing ambiguous requests at the front-end, and migrating to HTTP/2, which uses binary frames with explicit lengths and eliminates this ambiguity entirely.
