The host is installed with Python before 3.6.13, 3.7.x before 3.7.10, 3.8.x before 3.8.8 or 3.9.x before 3.9.2 and is prone to a web cache poisoning vulnerability. A flaw is present in urllib.parse.parse_qsl and urllib.parse.parse methods, which fails to properly handle issues in parameter cloaking. Successful exploitation could result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.