No exploitation reportedFix available

CVE-2021-44224

Q: Is CVE-2021-44224 actively exploited?

Active exploitation of CVE-2021-44224 has not been confirmed. Its EPSS score was 82.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-44224?

CVE-2021-44224 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.

No exploitation reported by the sources we read.

Published2021-12-20
WeaknessCWE-476

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).

Timeline

dates in UTC

2021-12-2012:15CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-44224?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-44224?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Oracle communications operations monitor

Branch	Affected	Fixed in	Source
4.0	= 4.0	no fix published	NVD
4.3	= 4.3	no fix published	NVD
4.4	= 4.4	no fix published	NVD
5.0	= 5.0	no fix published	NVD

Apple macos

Branch	Affected	Fixed in	Source
12.x	≥ 12.0.0, < 12.4	12.4	NVD
11.x	≥ 11.0, < 11.6.6	11.6.6	NVD
10.15	< 10.15.7	10.15.7	NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
34.x	= 34	no fix published	NVD
35.x	= 35	no fix published	NVD
36.x	= 36	no fix published	NVD

9 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.18.2read 2026-10-23
NVDCVSS 2.06.4read 2026-10-23
CNAweakness (CWE)CWE-476read 2026-10-23
NVDweakness (CWE)CWE-476read 2026-10-23
FIRST EPSSEPSS score82.3 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Published: 2021-12-20
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-44224?

Is CVE-2021-44224 actively exploited?

Active exploitation of CVE-2021-44224 has not been confirmed. Its EPSS score was 82.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-44224?

CVE-2021-44224 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.

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