CVE-2021-21330
In aiohttp before version 3.7.4 there is an open redirect vulnerability.
Does this matter?
Lower severity and a low EPSS score (1.91%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.91% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- aiohttp/aiohttp · debian/debian linux · fedoraproject/fedora
- Source
- security-advisories@github.com
EPSS 1.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst#374-2021-02-25Third Party Advisory
- https://github.com/aio-libs/aiohttp/commit/2545222a3853e31ace15d87ae0e2effb7da0c96bPatch, Third Party Advisory
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-v6wp-4m6f-gcjgThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FU7ENI54JNEK3PHEFGCE46DGMFNTVU6L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN3V7CZJRT4QFCVXB6LDPCJH7NAOFCA5/
- https://pypi.org/project/aiohttp/Product, Third Party Advisory
- https://security.gentoo.org/glsa/202208-19Third Party Advisory
- https://www.debian.org/security/2021/dsa-4864Third Party Advisory
- https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst#374-2021-02-25Third Party Advisory
- https://github.com/aio-libs/aiohttp/commit/2545222a3853e31ace15d87ae0e2effb7da0c96bPatch, Third Party Advisory
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-v6wp-4m6f-gcjgThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FU7ENI54JNEK3PHEFGCE46DGMFNTVU6L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN3V7CZJRT4QFCVXB6LDPCJH7NAOFCA5/
- https://pypi.org/project/aiohttp/Product, Third Party Advisory
- https://security.gentoo.org/glsa/202208-19Third Party Advisory
- https://www.debian.org/security/2021/dsa-4864Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.