Vulnerability · Published Dec 12, 2023 · Assigned by redhat
CVE-2023-5379Undertow: ajp request closes connection exceeding maxrequestsize
High 7.5
In plain English
A high-severity resource allocation without limits in Red Hat build of Quarkus from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 64% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | undertow | 2.3.18-1 | DEBIAN-CVE-2023-5379 |
| Ubuntu:25.10 | undertow | no fix listed | UBUNTU-CVE-2023-5379 |
| Ubuntu:26.04:LTS | undertow | no fix listed | UBUNTU-CVE-2023-5379 |
| Ubuntu:26.10 | undertow | no fix listed | UBUNTU-CVE-2023-5379 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- RHSA-2025:9582 vendor-advisory, x_refsource_REDHAT
- RHSA-2025:9583 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2023-5379 vdb-entry, x_refsource_REDHAT
- RHBZ#2242099 issue-tracking, x_refsource_REDHAT
- RHSA-2023:4509 vendor-advisory, x_refsource_REDHAT, x_transferred