Is CVE-2021-33193 actively exploited?

CVE-2021-33193 has no public evidence of in-the-wild exploitation as of 2025-05-01.

What is the CVSS score for CVE-2021-33193?

CVE-2021-33193 has a CVSS score of 7.5 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

How do I patch CVE-2021-33193?

Patch guidance is available from debian security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-33193.

Fix CVE-2021-33193 - HIGH debian debian linux

Q: Which products are affected by CVE-2021-33193?

7 products: debian debian linux, apache http server, fedoraproject fedora, fedoraproject fedora, tenable tenable.sc, and 2 more.

Description

A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: high
Availability: none
Weaknesses: NVD-CWE-Other

Metadata

Primary Vendor: DEBIAN
Published: 8/16/2021
Last Modified: 5/1/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

debian : debian_linuxapache : http_serverfedoraproject : fedorafedoraproject : fedoratenable : tenable.scoracle : secure_backuporacle : zfs_storage_appliance_kit

Remediation Guidance

Executive Summary

View on NIST NVD