6.5

CVE-2021-3733: fedoraproject extra_packages_for_enterprise_linux Uncontrolled Resource Consumption

Modified
AliasesMGASA-2021-0457RHSA-2021:4057UBUNTU-CVE-2021-3733
Published 07-03-2022Last modified 14-10-2026

Vulnerability summary

CVE-2021-3733 is a medium (CVSS 6.5) Uncontrolled Resource Consumption vulnerability in fedoraproject extra_packages_for_enterprise_linux. EPSS estimates a 4.80% chance of exploitation in the next 30 days, higher than 91.9% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Routine

Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
4.80%
0%100%
Low · +0.12 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 28 · Related 18
DLA-2808-1DLA-3432-1DLA-3477-1DLA-3980-1MGASA-2021-0435OPENSUSE-SU-2021:1418-1

Timeline

  1. 07-03-2022
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

Description

There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

4.80%

Chance of exploitation in the next 30 days

Percentile

92%

Versus all other CVEs

30-day change

Increase +0.12 pp

From 4.67% 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

1 found
  • referenceUnverified

    Exploit Reference (bugs.python.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

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

Redhat23 products
Ubuntu6 products
  • python3.4< 3.4.3-1ubuntu1~14.04.7+esm11
  • python3.5< 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1 | < 3.5.2-2ubuntu0~16.04.13+esm1
  • python3.6< 3.6.9-1~18.04ubuntu1.6
  • python3.7< 3.7.5-2ubuntu1~18.04.2
  • python3.8< 3.8.0-3ubuntu1~18.04.2 | < 3.8.10-0ubuntu1~20.04
Netapp4 products
Fedoraproject2 products
Debian1 product
  • pypy3< 7.3.5+dfsg-2
Mageia1 product
  • python< 2.7.18-7.3.mga8
Python1 product
  • pythonEOL< 3.6.14 | ≥ 3.7.0, < 3.7.11 | ≥ 3.8.0, < 3.8.10 | ≥ 3.9.0, < 3.9.5 | 3.10.0

7 vendors · 38 products

References

33 links
Show all 33 references