PSF-2021-1 urllib parse_qsl(): Web cache poisoning - semicolon as a query args separator

The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parseqsl and urllib.parse.parseqs by using a vector called parameter cloaking. When the attacker can...