HOMEVULNERABILITIESCVE-2021-41524
HIGH

CVE-2021-41524

CWE-476Published: October 5, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-41524 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Apache1 product(s)
http server
Fedora1 product(s)
fedora
netapp1 product(s)
cloud backup
Oracle1 product(s)
instantis enterprisetrack
Source: NVD CPE · 7 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://www.oracle.com/security-alerts/cpujan2022.html
PATCHhttps://www.oracle.com/security-alerts/cpujan2022.html
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/10/05/1
ADVISORYhttps://httpd.apache.org/security/vulnerabilities_24.html
ADVISORYhttps://security.gentoo.org/glsa/202208-20
ADVISORYhttps://security.netapp.com/advisory/ntap-20211029-0009/
ADVISORYhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/10/05/1
ADVISORYhttps://httpd.apache.org/security/vulnerabilities_24.html
ADVISORYhttps://security.gentoo.org/glsa/202208-20
ADVISORYhttps://security.netapp.com/advisory/ntap-20211029-0009/
ADVISORYhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ

All References (16)

→
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

Quick Facts

CVE IDCVE-2021-41524
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-476
CISA KEVNo
Affected4 vendor(s)
PublishedOct 5, 2021

Related CVEs (CWE-476)

CVE-2010-2495
10.0
CVE-2022-36648
10.0
CVE-2016-6604
9.8
CVE-2014-8241
9.8
CVE-2016-5690
9.8
CVE-2016-5689
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-41524 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2021-41524·NVD