6.1

CVE-2021-21330: Open redirect vulnerability in aiohttp

Modified
AliasesMGASA-2021-0161SUSE-RU-2022:3275-1SUSE-SU-2021:1313-1
Published 26-02-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-21330 is a medium (CVSS 6.1) URL Redirection to Untrusted Site vulnerability in aio-libs aiohttp. EPSS estimates a 1.91% chance of exploitation in the next 30 days, higher than 79.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 3.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.1/10
010
Medium · v3.1 (NVD)
EPSS score
1.91%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 1
OPENSUSE-SU-2026:11467-1RHSA-2021:4702

Timeline

  1. 26-02-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

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 metrics

7 scores · 5 sources · 3 versions

EPSS trend

Probability

1.91%

Chance of exploitation in the next 30 days

Percentile

80%

Versus all other CVEs

30-day change

No change 0.00 pp

From 1.91% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Suse8 products
  • python-aiohttp&distro=SUSE Linux Enterprise Module for Public Cloud 15 SP1< 3.6.0-150100.3.9.1 | < 3.4.4-3.6.1
  • python-aiohttp&distro=SUSE Linux Enterprise Module for Public Cloud 15 SP2< 3.6.0-150100.3.9.1 | < 3.4.4-3.6.1
  • python-aiohttp&distro=SUSE Linux Enterprise Module for Public Cloud 15 SP3< 3.6.0-150100.3.9.1
  • python-aiohttp&distro=SUSE Linux Enterprise Module for Public Cloud 15 SP4< 3.6.0-150100.3.9.1
  • python-typing_extensions&distro=SUSE Linux Enterprise Module for Public Cloud 15 SP1< 3.10.0.0-150100.3.3.1
Opensuse4 products
  • python-aiohttp&distro=openSUSE Leap 15.3< 3.6.0-150100.3.9.1
  • python-aiohttp&distro=openSUSE Leap 15.4< 3.6.0-150100.3.9.1
  • python-aiohttp&distro=openSUSE Tumbleweed< 3.8.5-2.1
  • python-typing_extensions&distro=openSUSE Leap 15.4< 3.10.0.0-150400.3.2.1
Debian2 products
  • python-aiohttp< 3.5.1-1+deb10u1 | < 3.7.4-1
  • debian_linuxEOL10.0
Aio-libs1 product
Aiohttp1 product
Fedoraproject1 product
Mageia1 product
  • python-aiohttp< 3.7.4-1.mga8
PyPI1 product
  • aiohttp< 2545222a3853e31ace15d87ae0e2effb7da0c96b | < 3.7.4
Ubuntu1 product
  • python-aiohttp< 3.0.1-1ubuntu0.1~esm1 | < 3.6.2-1ubuntu0.1~esm1

9 vendors · 20 products

References

31 links
Show all 31 references