Vulnerability in Squid Proxy Server Affects Request Handling

CVE-2019-12520

What is CVE-2019-12520?

A vulnerability in Squid Proxy Server, present in versions 4.7 through 5, allows an attacker to exploit the way requests are cached. The issue arises when an absolute URL, which may inadvertently include decoded UserInfo (username and password), is processed. An attacker can craft a request with an encoded username containing special characters, misleading Squid into serving its HTML instead of the legitimate content from the target domain. This manipulation is particularly concerning for Squid servers used as reverse proxies, enabling unauthorized access to sensitive features exclusive to reverse proxy operations.

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