CVE-2023-5379
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS — probability of exploitation (30 days)
1.0%
61.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-770
Published 2023-12-12 · modified 2026-08-04
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2023-12-12 — Published (NVD)
- 2026-08-04 — Last modified (NVD)
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).
Affected
References
- https://access.redhat.com/errata/RHSA-2025:9582
- https://access.redhat.com/errata/RHSA-2025:9583
- https://access.redhat.com/security/cve/CVE-2023-5379
- https://bugzilla.redhat.com/show_bug.cgi?id=2242099
- https://access.redhat.com/errata/RHSA-2023:4509
- https://access.redhat.com/security/cve/CVE-2023-5379
- https://bugzilla.redhat.com/show_bug.cgi?id=2242099