{"id":"CVE-2021-21330","aliases":["GHSA-v6wp-4m6f-gcjg","PYSEC-2021-76"],"url":"https://o3.security/vulnerability/CVE-2021-21330","summary":"`aiohttp` Open Redirect vulnerability (`normalize_path_middleware` middleware)","details":"aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. In aiohttp before version 3.7.4 there is an open redirect vulnerability. A maliciously crafted link to an aiohttp-based web-server could redirect the browser to a different website. It is caused by a bug in the `aiohttp.web_middlewares.normalize_path_middleware` middleware. This security problem has been fixed in 3.7.4. Upgrade your dependency using pip as follows \"pip install aiohttp >= 3.7.4\". If upgrading is not an option for you, a workaround can be to avoid using `aiohttp.web_middlewares.normalize_path_middleware` in your applications.","published":"2021-02-26T03:15:12.840Z","modified":"2026-08-07T11:49:02.490928007Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"aiohttp","fixedVersion":"3.7.4"}],"fix":{"url":"https://github.com/aio-libs/aiohttp/commit/2545222a3853e31ace15d87ae0e2effb7da0c96b","label":"aio-libs/aiohttp@2545222"},"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FU7ENI54JNEK3PHEFGCE46DGMFNTVU6L/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN3V7CZJRT4QFCVXB6LDPCJH7NAOFCA5/"},{"type":"ADVISORY","url":"https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst#374-2021-02-25"},{"type":"ADVISORY","url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-v6wp-4m6f-gcjg"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202208-19"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-4864"},{"type":"FIX","url":"https://github.com/aio-libs/aiohttp/commit/2545222a3853e31ace15d87ae0e2effb7da0c96b"},{"type":"PACKAGE","url":"https://pypi.org/project/aiohttp/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:49:02.490928007Z"}}