CVE-2022-31813: mod_proxy X-Forwarded-For dropped by hop-by-hop mechanism

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-06-09 · updated 2026-06-17
Weakness: CWE-348

Description

Apache HTTP Server 2.4.53 and earlier may not send the X-Forwarded-* headers to the origin server based on client side Connection header hop-by-hop mechanism. This may be used to bypass IP based authentication on the origin server/application.

Affected products

Apache HTTP Server: before 2.4.54 — fixed in 2.4.54
Fedoraproject Fedora: 35, 36
Clustered Data ONTAP: all versions

How to fix

Upgrade to a fixed version: Apache HTTP Server 2.4.54. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2022/06/08/8
https://httpd.apache.org/security/vulnerabilities_24.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7QUGG2QZWHTITMABFLVXA4DNYUOTPWYQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPY2BLEVJWFH34AX77ZJPLD2OOBYR6ND/
https://security.gentoo.org/glsa/202208-20
https://security.netapp.com/advisory/ntap-20220624-0005/
http://www.openwall.com/lists/oss-security/2022/06/08/8
https://httpd.apache.org/security/vulnerabilities_24.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7QUGG2QZWHTITMABFLVXA4DNYUOTPWYQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPY2BLEVJWFH34AX77ZJPLD2OOBYR6ND/
https://security.gentoo.org/glsa/202208-20
https://security.netapp.com/advisory/ntap-20220624-0005/

Get alerted when CVE-2022-31813 or the next vulnerability affects your stack