CVE-2023-5379
Undertow: ajp request closes connection exceeding maxrequestsize
No known exploitation. EPSS puts it in the 62nd percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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).
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
1.0% chance of exploitation activity in the next 30 days, which ranks it in the 62nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
8 events over 966 days, from the signal feeds we watch.
- Patch availablerecord updated
- OpenVAS check added
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
- jboss enterprise application platformOperating Systems / linux-distro
- single sign-onOperating Systems / linux-distro
- undertowOperating Systems / linux-distro
- Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7Enterprise Software
- Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7Operating Systems / linux-distro
- Red Hat build of QuarkusOSS Libraries / generic-library
- Red Hat Data Grid 8Databases / cache-message-queue
- Red Hat Decision Manager 7Enterprise Software / itsm-monitoring
And 7 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Scored 7.5 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity NoneNo integrity impact
- Availability NoneNo availability impact
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
References in the record
- access.redhat.com/errata/RHSA-2025:9582
- access.redhat.com/errata/RHSA-2025:9583
- access.redhat.com/security/cve/CVE-2023-5379
And 2 more references. See all after sign-in
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