CVE-2023-43656

Process-level code execution via vm2 sandbox escape

Published Sep 27, 2023 · Updated Sep 20, 2024

Code injection in Matrix.org Matrix Hookshot before 4.5.0 allows local users to escape its JavaScript sandbox through transformation functions. GenericHookConnection passes administrator-enabled, user-supplied transformationFunction code to vm2 NodeVM.run, whose discontinued sandbox can be escaped. Exposure requires generic.allowJsTransformationFunctions and permission for untrusted users to supply code; escape permits code execution within the Hookshot process.

CVSS severity5.6
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Matrix.org Matrix Hookshot before 4.5.0 allows local users to escape its JavaScript sandbox through transformation functions. GenericHookConnection passes administrator-enabled, user-supplied transformationFunction code to vm2 NodeVM.run, whose discontinued sandbox can be escaped. Exposure requires generic.allowJsTransformationFunctions and permission for untrusted users to supply code; escape permits code execution within the Hookshot process.

The record

CVE
CVE-2023-43656
Published
Sep 27, 2023
Updated
Sep 20, 2024
Vendor
Matrix.org
Product
Matrix Hookshot
Classifications
CWE-74, CWE-94, T1059.007
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 20, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Matrix.org · Matrix Hookshotversion=< 4.5.0

Published CVSS scores

5.6GitHub CNACVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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