Security Resilience

CVE-2023-42794

Apache Tomcat 8.5.85 – 8.5.94

Published
10 October 2023
Modified
08 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.023 83th percentile
Risk Priority 50 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-42794 is a medium-severity Incomplete Cleanup (CWE-459) vulnerability in Apache Tomcat. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked in the top 17% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

Incomplete Cleanup vulnerability in Apache Tomcat. The internal fork of Commons FileUpload packaged with Apache Tomcat 9.0.70 through 9.0.80 and 8.5.85 through 8.5.93 included an unreleased, in progress refactoring that exposed a potential denial of service on Windows if a…

more

web application opened a stream for an uploaded file but failed to close the stream. The file would never be deleted from disk creating the possibility of an eventual denial of service due to the disk being full. Other, EOL versions may also be affected. Users are recommended to upgrade to version 9.0.81 onwards or 8.5.94 onwards, which fixes the issue.

CWE(s)
CWE-459

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
attack.mitre.org →
T1016.001 Internet Connection Discovery Discovery
Adversaries may check for Internet connectivity on compromised systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-31650Same product: Apache Tomcat
CVE-2023-42795Same product: Apache Tomcat
CVE-2026-29146Same product: Apache Tomcat
CVE-2025-55754Same product: Apache Tomcat
CVE-2026-53434Same product: Apache Tomcat
CVE-2026-65927Same product: Apache Tomcat
CVE-2026-43514Same product: Apache Tomcat
CVE-2025-46701Same product: Apache Tomcat
CVE-2026-43513Same product: Apache Tomcat
CVE-2025-48988Same product: Apache Tomcat

Affected Assets

apache
tomcat
8.5.85 — 8.5.94 · 9.0.70 — 9.0.81

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.4.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-4 Information in Shared System Resources
addresses: CWE-459

Mandates complete sanitization during cleanup so that shared resources (memory, caches, buffers) do not retain data across subjects.

SI-12 Information Management and Retention
addresses: CWE-459

Operational retention schedules mandate complete cleanup of temporary or residual sensitive data after use.

SI-14 Non-persistence
addresses: CWE-459

Termination of the non-persistent artifact guarantees cleanup of temporary state, directly countering incomplete cleanup weaknesses.

SI-17 Fail-safe Procedures
addresses: CWE-459

Fail-safe procedures can explicitly require cleanup of temporary state, resources, or privileges on failure to avoid leaving the system in an inconsistent state.

SI-21 Information Refresh
addresses: CWE-459

The explicit delete step when information is no longer needed implements the cleanup that this weakness omits.

SR-12 Component Disposal
addresses: CWE-459

Enforces complete cleanup and sanitization steps during disposal, closing gaps that leave data remnants on retired components.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.AM-08 partial match
blocks

Life-cycle management encompasses disposal of temporary resources but does not specifically target runtime cleanup bugs.

PR.DS-10 partial match
blocks

Explicitly calls for removing sensitive data after use, directly addressing one class of incomplete cleanup.

PR.PS-06 partial match
blocks

Secure-development practices and coding standards normally require proper resource release and cleanup.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References