CVE-2023-5379

What it is

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).

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

1.0% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-12-12 22:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-05 12:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.0% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-12-12 22:15 UTC

Last modified

2026-11-05 12:17 UTC

Exploit probability

1.0% · EPSS, next 30 days

Weakness

CWE-770 · Allocation without limits

Record status

Modified

Affected

• Redhat Jboss Enterprise Application Platform
• Redhat Jboss Enterprise Application Platform 7.0.0
• Redhat Single sign-on 7.0
• Redhat Undertow

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-5379.md and follow it. Check whether this project is affected by CVE-2023-5379. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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