Is CVE-2021-21330 in the CISA KEV catalog?

No. CVE-2021-21330 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-21330?

CVE-2021-21330 has a CVSS v3 base score of 3.1 (LOW).

What is the EPSS score for CVE-2021-21330?

CVE-2021-21330 has an EPSS score of 1.91% (77th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-21330?

Upgrade python-aiohttp on debian 11 to 3.7.4-1 or later. Fixes are available for 3 affected products.

CVE & CISA-KEV Catalog

CVE-2021-21330

LOWEPSS 77th pctl

3.1

CVSS v3

NVD

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.

CWE-601Open Redirect

How to fix

Remediation Available

python-aiohttpDebian

Fixed in:3.7.4-1CVE-2021-21330

python-aiohttpUbuntu

Fixed in:3.0.1-1ubuntu0.1~esm1USN-5386-1

Fixed in:3.6.2-1ubuntu0.1~esm1USN-5386-1

python3-aiohttpUbuntu

Fixed in:3.0.1-1ubuntu0.1~esm1USN-5386-1

Fixed in:3.6.2-1ubuntu0.1~esm1USN-5386-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

Exploit Intelligence

1.91%probability of exploitation in 30 days

77thpercentile

Elevated risk: more likely to be exploited than 77% of all known CVEs.

References

Patch1

github.com

Third-Party Advisory5

Other references2

Related Vulnerabilities

Other CWE-601 (Open Redirect) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-4123	High	7.6	98%	-	Fix
CVE-2018-11784	Medium	4.3	94%	-	Fix
CVE-2021-22881	Medium	6.1	87%	-	Fix
CVE-2022-45402	Medium	6.1	82%	-	Fix
CVE-2017-1000117	High	8.8	78%	-	Fix
CVE-2019-10098	Medium	6.1	74%	-	Fix

Embed a live status badge for CVE-2021-21330

Markdown

[![CVE-2021-21330](https://tridentstack.com/cve/badge/CVE-2021-21330.svg)](https://tridentstack.com/cve/CVE-2021-21330)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-21330"><img src="https://tridentstack.com/cve/badge/CVE-2021-21330.svg" alt="CVE-2021-21330"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.