CVE-2021-44224

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).

• CWE-476
• CWE-476

• http://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
• http://seclists.org/fulldisclosure/2022/May/33Mailing List, Third Party Advisory
• http://seclists.org/fulldisclosure/2022/May/35Mailing List, Third Party Advisory
• http://seclists.org/fulldisclosure/2022/May/38Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/12/20/3Mailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BFSWOH4X77CV7AH7C4RMHUBDWKQDL4YH/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGWILBORT67SHMSLYSQZG2NMXGCMPUZO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X73C35MMMZGBVPQQCH7LQZUMYZNQA5FO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7H26WJ6TPKNWV3QKY4BHKUKQVUTZJTD/
• https://security.gentoo.org/glsa/202208-20Third Party Advisory
• https://security.netapp.com/advisory/ntap-20211224-0001/Third Party Advisory
• https://support.apple.com/kb/HT213255Third Party Advisory
• https://support.apple.com/kb/HT213256Third Party Advisory
• https://support.apple.com/kb/HT213257Third Party Advisory
• https://www.debian.org/security/2022/dsa-5035Third Party Advisory
• https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
• https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
• https://www.tenable.com/security/tns-2022-01Third Party Advisory
• https://www.tenable.com/security/tns-2022-03Third Party Advisory
• http://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
• http://seclists.org/fulldisclosure/2022/May/33Mailing List, Third Party Advisory
• http://seclists.org/fulldisclosure/2022/May/35Mailing List, Third Party Advisory
• http://seclists.org/fulldisclosure/2022/May/38Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/12/20/3Mailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BFSWOH4X77CV7AH7C4RMHUBDWKQDL4YH/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGWILBORT67SHMSLYSQZG2NMXGCMPUZO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X73C35MMMZGBVPQQCH7LQZUMYZNQA5FO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7H26WJ6TPKNWV3QKY4BHKUKQVUTZJTD/
• https://security.gentoo.org/glsa/202208-20Third Party Advisory
• https://security.netapp.com/advisory/ntap-20211224-0001/Third Party Advisory
• https://support.apple.com/kb/HT213255Third Party Advisory
• https://support.apple.com/kb/HT213256Third Party Advisory
• https://support.apple.com/kb/HT213257Third Party Advisory
• https://www.debian.org/security/2022/dsa-5035Third Party Advisory
• https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
• https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
• https://www.tenable.com/security/tns-2022-01Third Party Advisory
• https://www.tenable.com/security/tns-2022-03Third Party Advisory

Published

Dec 20, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
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