Arch Linux Security Advisory ASA-202102-28 ========================================== Severity: Medium Date : 2021-02-20 CVE-ID : CVE-2021-23336 Package : python-django Type : url request injection Remote : Yes Link : https://security.archlinux.org/AVG-1593 Summary ======= The package python-django before version 3.1.7-1 is vulnerable to url request injection. Resolution ========== Upgrade to 3.1.7-1. # pacman -Syu "python-django>=3.1.7-1" The problem has been fixed upstream in version 3.1.7. Workaround ========== None. Description =========== 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.parse_qsl and urllib.parse.parse_qs 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 can 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. The package python-django contains a copy of urllib.parse.parse_qsl() which was added to backport some security fixes. A further security fix has been issued in versions 3.1.7, 3.0.13 and 2.2.19 such that parse_qsl() no longer allows using ; as a query parameter separator by default. Impact ====== A remote attacker is able to insert malicious requests in the web proxy cache. References ========== https://snyk.io/vuln/SNYK-UPSTREAM-PYTHONCPYTHON-1074933 https://snyk.io/blog/cache-poisoning-in-popular-open-source-packages/ https://bugs.python.org/issue42967 https://github.com/python/cpython/pull/24297 https://github.com/python/cpython/commit/c9f07813ab8e664d8c34413c4fc2d4f86c0... https://www.djangoproject.com/weblog/2021/feb/19/security-releases/ https://github.com/django/django/commit/8f6d431b08cbb418d9144b976e7b97254660... https://security.archlinux.org/CVE-2021-23336