CVE-2021-41524

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

25.17% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 97.7% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-10-05 08:40Z5 YR AGO

Last updated

2024-08-04 03:15Z2 YR AGO

Reserved

2021-09-20

Assigning CNA

apache

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.1

Document digest

3c2efa7b8cbc3851dbea97819400ef9e1c75eab79a3cce14254f437a0572c263

• httpd.apache.orghttps://httpd.apache.org/security/vulnerabilities_24.htmlx_refsource_MISC
• www.openwall.com[oss-security] 20211005 CVE-2021-41524: Apache HTTP Server: null pointer dereference in h2 fuzzinghttp://www.openwall.com/lists/oss-security/2021/10/05/1mailing-listx_refsource_MLIST
• lists.fedoraproject.orgFEDORA-2021-5d2d4b6ac5https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/vendor-advisoryx_refsource_FEDORA
• tools.cisco.com20211007 Apache HTTP Server Vulnerabilties: October 2021https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZvendor-advisoryx_refsource_CISCO
• lists.fedoraproject.orgFEDORA-2021-f94985afcahttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/vendor-advisoryx_refsource_FEDORA
• www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.htmlx_refsource_MISC
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20211029-0009/x_refsource_CONFIRM
• security.gentoo.orgGLSA-202208-20https://security.gentoo.org/glsa/202208-20vendor-advisoryx_refsource_GENTOO