CVE-2023-5379

Undertow: ajp request closes connection exceeding maxrequestsize

HIGH
7.5
CVSS Score
Published: December 12, 2023 at 09:54 PM UTC
Updated: August 4, 2026 at 10:17 PM UTC
3 products affected across 1 vendorJBoss Enterprise Application PlatformSingle Sign onUndertow

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 0:1.0.12-1.Final_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.0.12-6.Final_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.0.13-1.Final_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.0.21-1.Final_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.1.14-1.Final_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.10.17-1.Final_redhat_00001.1.el7eap (unaffected)
Vendor states this is fixed in 0:1.4.18-16.SP14_redhat_00001.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:1.7.2-16.Final_redhat_00017.1.el7eap (unaffected)
Vendor states this is fixed in 0:2.0.41-4.SP5_redhat_00001.1.el7eap (unaffected)
Vendor states this is fixed in 0:2.10.4-2.redhat_00006.1.el7eap (unaffected)
Vendor states this is fixed in 0:2.10.4-3.redhat_00006.1.el7eap (unaffected)
Vendor states this is fixed in 0:2.10.4-5.redhat_00006.1.el7eap (unaffected)
Vendor states this is fixed in 0:2.8.11.6-3.SP1_redhat_00003.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:3.0.1-4.b08_redhat_00005.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:4.0.12-1.Final_redhat_00002.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:4.1.63-2.Final_redhat_00003.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:4.1.63-5.Final_redhat_00003.1.el7eap (unaffected)
Vendor states this is fixed in 0:5.1.17-3.Final_redhat_00004.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:7.1.11-4.GA_redhat_00002.1.ep7.el7 (unaffected)
Vendor states this is fixed in 0:7.3.14-3.GA_redhat_00002.1.el7eap (unaffected)
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-770

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