Cesanta MJS 1.26 mjs.c mjs_mk_string denial of service

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.4	$0-$5k	0.00

Summaryinfo

A vulnerability described as problematic has been identified in Cesanta MJS 1.26. Affected by this vulnerability is the function mjs_mk_string of the file mjs.c. The manipulation results in denial of service. This vulnerability is reported as CVE-2023-30087. The attack requires a local approach. No exploit exists.

Detailsinfo

A vulnerability classified as problematic has been found in Cesanta MJS 1.26. Affected is the function mjs_mk_string of the file mjs.c. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. CVE summarizes:

Buffer Overflow vulnerability found in Cesanta MJS v.1.26 allows a local attacker to cause a denial of service via the mjs_mk_string function in mjs.c.

The weakness was disclosed 05/09/2023 as 244. The advisory is shared for download at github.com. This vulnerability is traded as CVE-2023-30087 since 04/07/2023. There are known technical details, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-34520). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Cesanta

Name

Version

1.26

License

commercial

Website

Product: https://github.com/cesanta/mjs/

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.3
VulDB Temp Score: 3.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

04/07/2023 🔍
05/09/2023 +32 days 🔍
05/09/2023 +0 days 🔍
12/20/2025 +956 days 🔍

Sourcesinfo

Product: github.com

Advisory: 244
Status: Confirmed

CVE: CVE-2023-30087 (🔍)
GCVE (CVE): GCVE-0-2023-30087
GCVE (VulDB): GCVE-100-228492
EUVD: 🔍

Entryinfo

Created: 05/09/2023 20:53
Updated: 12/20/2025 04:58
Changes: 05/09/2023 20:53 (40), 06/01/2023 17:13 (11), 12/20/2025 04:58 (16)
Complete: 🔍
Cache ID: 216::103