Skip to content
VulniPulse
High7.5Red Hat Linux

High [CVE-2023-5379] Undertow: ajp request closes connection exceeding maxrequestsize

This high-severity Red Hat Linux advisory covers CVE-2023-5379 affecting Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7, Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7, Red Hat Single Sign-On 7.

CVE-2023-5379 Published Dec 12, 2023Updated by vendor Aug 4, 2026
Affected products & platforms
Red Hat LinuxRed Hat Enterprise Linux
Open vendor advisory

Android app · Google Play

Monitor future Red Hat Linux CVEs from your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.

Matching phone alertsOptional email delivery

Summary

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).

Affected products named by the advisory: Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7; Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7; Red Hat JBoss Enterprise Application Platform 7; Red Hat Single Sign-On 7.

Affected versions

No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.

Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.

Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source

Mitigation

The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.

Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source

Discussion(0)

No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.

Sign in to join the discussion.