CVE-2021-44224

Possible NULL dereference or SSRF in forward proxy configurations in Apache HTTP Server 2.4.51 and earlier

Description

A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).

Category

8.2
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 12.65% Top 10%
Vendor Advisory fedoraproject.org Vendor Advisory debian.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org Vendor Advisory apache.org
Affected: Apache Software Foundation Apache HTTP Server
Published at:
Updated at:

References

Link Tags
http://httpd.apache.org/security/vulnerabilities_24.html vendor advisory
http://www.openwall.com/lists/oss-security/2021/12/20/3 third party advisory mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BFSWOH4X77CV7AH7C4RMHUBDWKQDL4YH/ vendor advisory
https://www.debian.org/security/2022/dsa-5035 third party advisory vendor advisory
https://www.oracle.com/security-alerts/cpujan2022.html third party advisory patch
https://security.netapp.com/advisory/ntap-20211224-0001/ third party advisory
https://www.tenable.com/security/tns-2022-01 third party advisory
https://www.tenable.com/security/tns-2022-03 third party advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGWILBORT67SHMSLYSQZG2NMXGCMPUZO/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7H26WJ6TPKNWV3QKY4BHKUKQVUTZJTD/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X73C35MMMZGBVPQQCH7LQZUMYZNQA5FO/ vendor advisory
https://www.oracle.com/security-alerts/cpuapr2022.html third party advisory patch
https://support.apple.com/kb/HT213257 third party advisory
https://support.apple.com/kb/HT213256 third party advisory
https://support.apple.com/kb/HT213255 third party advisory
http://seclists.org/fulldisclosure/2022/May/33 third party advisory mailing list
http://seclists.org/fulldisclosure/2022/May/35 third party advisory mailing list
http://seclists.org/fulldisclosure/2022/May/38 third party advisory mailing list
https://security.gentoo.org/glsa/202208-20 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-44224?
CVE-2021-44224 has been scored as a high severity vulnerability.
How to fix CVE-2021-44224?
To fix CVE-2021-44224, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-44224 being actively exploited in the wild?
It is possible that CVE-2021-44224 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~13% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-44224?
CVE-2021-44224 affects Apache Software Foundation Apache HTTP Server.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.