CVE-2021-44224

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

82.30% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.6% of scored records. A rank, not a probability.

NVD base score

8.2 (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:L/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

2021-12-20 11:20Z4 YR AGO

Last updated

2024-08-04 04:17Z2 YR AGO

Reserved

2021-11-25

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
• CWE-918Server-Side Request Forgery (SSRF)Base

Data version

5.1

Document digest

e431bff77ea8d0d9eb68a36b385f850315f99674bb756e0cf28db8ff377e7cfe

• httpd.apache.orghttp://httpd.apache.org/security/vulnerabilities_24.htmlx_refsource_MISC
• www.openwall.com[oss-security] 20211220 CVE-2021-44224: Apache HTTP Server: Possible NULL dereference or SSRF in forward proxy configurations in Apache HTTP Server 2.4.51 and earlierhttp://www.openwall.com/lists/oss-security/2021/12/20/3mailing-listx_refsource_MLIST
• lists.fedoraproject.orgFEDORA-2021-29a536c2aehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BFSWOH4X77CV7AH7C4RMHUBDWKQDL4YH/vendor-advisoryx_refsource_FEDORA
• www.debian.orgDSA-5035https://www.debian.org/security/2022/dsa-5035vendor-advisoryx_refsource_DEBIAN
• www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.htmlx_refsource_MISC
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20211224-0001/x_refsource_CONFIRM
• www.tenable.comhttps://www.tenable.com/security/tns-2022-01x_refsource_CONFIRM
• www.tenable.comhttps://www.tenable.com/security/tns-2022-03x_refsource_CONFIRM
• lists.fedoraproject.orgFEDORA-2022-b4103753e9https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGWILBORT67SHMSLYSQZG2NMXGCMPUZO/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2022-21264ec6dbhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7H26WJ6TPKNWV3QKY4BHKUKQVUTZJTD/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2022-78e3211c55https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X73C35MMMZGBVPQQCH7LQZUMYZNQA5FO/vendor-advisoryx_refsource_FEDORA
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.htmlx_refsource_MISC
• support.apple.comhttps://support.apple.com/kb/HT213257x_refsource_CONFIRM
• support.apple.comhttps://support.apple.com/kb/HT213256x_refsource_CONFIRM
• support.apple.comhttps://support.apple.com/kb/HT213255x_refsource_CONFIRM
• seclists.org20220516 APPLE-SA-2022-05-16-4 Security Update 2022-004 Catalinahttp://seclists.org/fulldisclosure/2022/May/33mailing-listx_refsource_FULLDISC
• seclists.org20220516 APPLE-SA-2022-05-16-3 macOS Big Sur 11.6.6http://seclists.org/fulldisclosure/2022/May/35mailing-listx_refsource_FULLDISC
• seclists.org20220516 APPLE-SA-2022-05-16-2 macOS Monterey 12.4http://seclists.org/fulldisclosure/2022/May/38mailing-listx_refsource_FULLDISC
• security.gentoo.orgGLSA-202208-20https://security.gentoo.org/glsa/202208-20vendor-advisoryx_refsource_GENTOO