Cyber Resilience

CVE-2023-39943

Memory Safety in Ashlar Cobalt ≤ 12.4.1204.200

Memory Safety
Published
04 February 2025
Modified
16 September 2025
CVSS Score v4 8.4
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0020 10th percentile
Risk Priority 55 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-2023-39943 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Ashlar Cobalt. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-39943 is a vulnerability in Ashlar-Vellum Cobalt versions prior to v12 SP2 Build (1204.200), where the application fails to properly validate user-supplied data during XE file parsing. This flaw, classified under CWE-787 (Out-of-bounds Write), can result in an out-of-bounds write condition. The vulnerability carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.

A local attacker can exploit this vulnerability by crafting a malicious XE file and tricking a user into opening it within the affected application, requiring no privileges (PR:N) and low complexity (AC:L), though user interaction is necessary (UI:R). Successful exploitation enables arbitrary code execution in the context of the current process, granting the attacker high levels of control over confidentiality, integrity, and availability.

Mitigation guidance is available in the CISA ICS Advisory ICSA-23-299-03, accessible at https://www.cisa.gov/news-events/ics-advisories/icsa-23-299-03.

EU & UK References

Vulnerability Data

In Ashlar-Vellum Cobalt versions prior to v12 SP2 Build (1204.200), the affected application lacks proper validation of user-supplied data when parsing XE files. This could lead to an out-of-bounds write. An attacker could leverage this vulnerability to execute arbitrary code…

more

in the context of the current process.

CWE(s)
CWE-787

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-34293Same product: Ashlar Cobalt
CVE-2023-34305Same product: Ashlar Cobalt
CVE-2024-13048Same product: Ashlar Cobalt
CVE-2024-13046Same product: Ashlar Cobalt
CVE-2025-2020Same product: Ashlar Cobalt
CVE-2024-13044Same product: Ashlar Cobalt
CVE-2023-34292Same product: Ashlar Cobalt
CVE-2023-34286Same product: Ashlar Cobalt
CVE-2023-34291Same product: Ashlar Cobalt
CVE-2023-34290Same product: Ashlar Cobalt

Affected Assets

ashlar
cobalt
≤ 12.4.1204.200

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

SI-10 Information Input Validation partial match

Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.

SI-16 Memory Protection partial match

Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.

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-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

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 in development and acceptance can detect and prevent out-of-bounds write defects.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory handling.

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

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

A.8.32 Change management partial match
prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References