Cyber Resilience

CVE-2023-31125

Socket Engine.Io 5.1.0 – 6.4.2

Published
08 May 2023
Modified
13 February 2025
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.013 68th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2023-31125 is a medium-severity Uncaught Exception (CWE-248) vulnerability in Socket Engine.Io. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 32% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

Engine.IO is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for Socket.IO. An uncaught exception vulnerability was introduced in version 5.1.0 and included in version 4.1.0 of the `socket.io` parent package. Older versions are not impacted. A specially crafted HTTP…

more

request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process. This impacts all the users of the `engine.io` package, including those who use depending packages like `socket.io`. This issue was fixed in version 6.4.2 of Engine.IO. There is no known workaround except upgrading to a safe version.

CWE(s)
CWE-248NVD-CWE-Other

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-59725Same product: Socket Engine.Io
CVE-2026-59724Same product: Socket Engine.Io
CVE-2023-22477Shared CWE-248
CVE-2026-14181Shared CWE-248
CVE-2025-20176Shared CWE-248
CVE-2024-34363Shared CWE-248
CVE-2026-32314Shared CWE-248
CVE-2025-20754Shared CWE-248
CVE-2024-58369Shared CWE-248
CVE-2023-4785Shared CWE-248

Affected Assets

socket
engine.io
5.1.0 — 6.4.2

Mitigating Controls

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-24 Fail in Known State
addresses: CWE-248

Prevents abrupt termination from uncaught exceptions by requiring a defined, preserved-state failure mode.

SI-17 Fail-safe Procedures
addresses: CWE-248

Requires pre-defined safe responses for uncaught exceptions so they do not result in undefined or insecure program termination.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices explicitly require structured exception handling to prevent uncaught exceptions from reaching production.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect uncaught exceptions before production deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes exception-handling standards that reduce uncaught exceptions.

A.8.26 Application security requirements partial match
prevents

Application security requirements typically mandate robust error and exception handling.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles call for centralized, comprehensive exception management.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require catching and handling exceptions to prevent crashes or leaks.

References