CVE-2023-39943

Code execution via malformed XE file parsing

Published Feb 4, 2025 · Updated Feb 5, 2025

Out-of-bounds write in Ashlar-Vellum Cobalt before v12 SP2 Build (1204.200) allows attackers to execute code via a crafted XE file. The XE-file parser fails to validate user-supplied data before writing beyond the intended memory buffer. The same affected range applies to Cobalt Share, Xenon, Argon, and Lithium; exploitation requires a user to open a malicious XE file, and code runs in the current process.

CVSS severity8.4
High
EPSS probability0.20%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Ashlar-Vellum Cobalt before v12 SP2 Build (1204.200) allows attackers to execute code via a crafted XE file. The XE-file parser fails to validate user-supplied data before writing beyond the intended memory buffer. The same affected range applies to Cobalt Share, Xenon, Argon, and Lithium; exploitation requires a user to open a malicious XE file, and code runs in the current process.

The record

CVE
CVE-2023-39943
Published
Feb 4, 2025
Updated
Feb 5, 2025
Vendor
Ashlar-Vellum
Product
Cobalt
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 5, 2025Record 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=0 <v12 SP2 Build (1204.200)

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Ashlar-Vellum · Cobaltversion=0 <v12 SP2 Build (1204.200)
Ashlar-Vellum · Cobalt Shareversion=0 <v12 SP2 Build (1204.200)
Ashlar-Vellum · Xenonversion=0 <v12 SP2 Build (1204.200)
Ashlar-Vellum · Argonversion=0 <v12 SP2 Build (1204.200)
Ashlar-Vellum · Lithium CADversion=0 <v12 SP2 Build (1204.200)

Published CVSS scores

7.8ICS-CERTCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.4ICS-CERTCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File

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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