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

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.

Published: 2022-06-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-31813 is rated High Risk (72.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.14%). EPSS rose +3.10% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-31813

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 3.14% +3.10%
2 2026-02-03 0.05% 0.04% -0.01%
3 2026-02-01 — 0.05% —

Full EPSS history (30 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-31813

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2022-31813

OS Trackers for CVE-2022-31813

vendor priority summary link
alpine — CVE-2022-31813: 1 source package rows (apache2); 7 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2022-31813
debian not yet assigned CVE-2022-31813 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-31813
gentoo high CVE-2022-31813: 1 GLSA(s) (202208-20), 2 atom(s) (app-admin/apache-tools, www-servers/apache); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-31813
redhat medium — https://access.redhat.com/security/cve/CVE-2022-31813
suse medium CVE-2022-31813 severity moderate: SUSE including 319 source package names (2.8-13.5:apache2-utils-2.4.51-150400.6.3.1, 4.3.1.9.7.1:apache2-2.4.51-150400.6.3.1, …), 658 product×package rows across 101 product lines (Container bci/php-apache, Container suse/manager/4.3/proxy-httpd, … (101 product lines)): Fixed 427, Known Affected 231. https://www.suse.com/security/cve/CVE-2022-31813/
ubuntu medium CVE-2022-31813 medium priority: Ubuntu including 1 source packages (apache2), 8 status rows across 8 suites (bionic, focal, impish, jammy, kinetic, trusty, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2022-31813

Affected software / configurations for CVE-2022-31813

Vendor Product Version Raw CPE
apache http_server < 2.4.54 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
netapp clustered_data_ontap — cpe:2.3:a:netapp:clustered_data_ontap:-:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*

References for CVE-2022-31813

cvelogic Threat Intelligence