CVE-2021-41524

Name: CVE-2021-41524
Creator: NVD / NIST
Published: 2021-10-05T09:15:07.427+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 24.98%

Last modified Jun 17, 2026

CVE-2021-41524 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. EPSS estimates a 24.98% chance of exploitation in the next 30 days.

Description

While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49. No exploit is known to the project.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

24.98%

97.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	Http Server	2.4.49
Fedoraproject	Fedora	34
Fedoraproject	Fedora	35
Oracle	Instantis Enterprisetrack	17.1
Oracle	Instantis Enterprisetrack	17.2
Oracle	Instantis Enterprisetrack	17.3
Netapp	Cloud Backup	All versions

References

http://www.openwall.com/lists/oss-security/2021/10/05/1Mailing List, Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/
https://security.gentoo.org/glsa/202208-20Third Party Advisory
https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZThird Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/05/1Mailing List, Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/
https://security.gentoo.org/glsa/202208-20Third Party Advisory
https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZThird Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory

Timeline

Published: Oct 5, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41524?

How severe is CVE-2021-41524?

CVE-2021-41524 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 24.98% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41524?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-41524?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST