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 vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Score 0.013 70th percentile

Risk Priority 53 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-2023-31125 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 Steganography (T1001.002); ranked in the top 30% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2023-1610

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…

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-248 NVD-CWE-Other

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.002 Steganography Command And Control

Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.

attack.mitre.org →

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 →

T1007 System Service Discovery Discovery

Adversaries may try to gather information about registered local system services.

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 →

T1020.001 Traffic Duplication Exfiltration

Adversaries may leverage traffic mirroring in order to automate data exfiltration over compromised infrastructure.

attack.mitre.org →

T1021 Remote Services Lateral Movement

Adversaries may use [Valid Accounts](https://attack.

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-2025-3083Shared CWE-248

CVE-2025-23166Shared CWE-248

CVE-2026-48038Shared CWE-248

CVE-2026-48069Shared CWE-248

CVE-2022-51009Shared CWE-248

CVE-2026-62985Shared CWE-248

CVE-2025-32944Shared CWE-248

CVE-2024-58357Shared 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 partial match

blocks

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.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