HTTP Request Splitting Vulnerability in Squid Proxy Server

CVE-2020-15811

What is CVE-2020-15811?

A vulnerability exists in the Squid Proxy Server that can be exploited through incorrect data validation. Specifically, it enables attackers to perform HTTP Request Splitting attacks which can affect both HTTP and HTTPS traffic. This vulnerability allows malicious clients to bypass local security measures, potentially leading to cache poisoning. By manipulating the Transfer-Encoding header, an attacker can embed a second request within a successfully parsed request, which is then misinterpreted by Squid. As a result, Squid may deliver corrupt responses to clients, compromising the integrity of any downstream caches.

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