CVE-2020-28476

A flaw was found in python-tornado. All versions of package tornado are vulnerable to Web Cache Poisoning by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This issue results in malicious requests cached as completely safe ones. The highest threat from this vulnerability is to integrity and system availability.