CVE-2021-41524: apache software foundation apache http server NULL Pointer Dereference
Vulnerability summary
CVE-2021-41524 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in apache software foundation apache http server. EPSS estimates a 25.17% chance of exploitation in the next 30 days, higher than 97.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2Timeline
- 05-10-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
25.17%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
0.00 pp
From 25.17% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- apache2< 2.4.50-r0
Apache1 product
- http_server2.4.49
Apache software foundation1 product
- apache http server2.4.49
Debian1 product
- apache2< 2.4.50-1
Fedoraproject1 product
- fedoraEOL34 | 35
Netapp1 product
Oracle1 product
- instantis_enterprisetrack17.1 | 17.2 | 17.3
7 vendors · 7 products
References
11 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZVendor AdvisoryX Refsource CISCOThird Party Advisory
