CVE-2023-5379

Name: CVE-2023-5379
Creator: NVD / NIST
Published: 2023-12-12T22:15:22.41+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.02%

Last modified Jun 17, 2026

CVE-2023-5379 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. EPSS estimates a 1.02% chance of exploitation in the next 30 days.

Description

A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.02%

58.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Redhat	Jboss Enterprise Application Platform	All versions
Redhat	Jboss Enterprise Application Platform	7.0.0
Redhat	Single Sign-On	7.0
Redhat	Undertow	All versions

References

https://access.redhat.com/errata/RHSA-2025:9582
https://access.redhat.com/errata/RHSA-2025:9583
https://access.redhat.com/security/cve/CVE-2023-5379Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2242099Issue Tracking
https://access.redhat.com/errata/RHSA-2023:4509Vendor Advisory
https://access.redhat.com/security/cve/CVE-2023-5379Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2242099Issue Tracking

Timeline

Published: Dec 12, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-5379?

How severe is CVE-2023-5379?

CVE-2023-5379 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2023-5379?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-5379?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST