HOMEVULNERABILITIESCVE-2023-43338
CRITICAL

CVE-2023-43338

CWE-787Published: September 23, 2023· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

Cesanta mjs v2.20.0 was discovered to contain a function pointer hijacking vulnerability via the function mjs_get_ptr(). This vulnerability allows attackers to execute arbitrary code via a crafted input.

NVD Source

Risk Analysis

Cesanta mjs contains a function pointer hijacking vulnerability that allows arbitrary code execution via crafted input. The critical CVSS score highlights the danger of this memory-related flaw.

No public exploit is currently known, and it is not tracked in the KEV catalog. The vulnerability is remotely exploitable.

Recommended Action

Update to a version of mjs that addresses the function pointer vulnerability.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2023-43338 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

cesanta1 product(s)
mjs
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (2)

https://github.com/cesanta/mjs/issues/250Exploit · Issue Tracking · Vendor Advisory
https://github.com/cesanta/mjs/issues/250Exploit · Issue Tracking · Vendor Advisory

Quick Facts

CVE IDCVE-2023-43338
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-787
CISA KEVNo
Affected1 vendor(s)
PublishedSep 23, 2023

Related CVEs (CWE-787)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2023-43338 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.