TI-2021-18544 Aliases CVE-2021-42023 GHSA-x8jw-8x39-62fp

Insufficiently protected credentials in Siemens ModelSim Simulation

LOW 30CWE-522Published 2021-12-14 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: High · None · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-522.

Summary

A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.

Why it matters now

EPSS 0.00582 48th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Siemens	ModelSim Simulation	All versions	—	No fix listed	CNA
Siemens	Questa Simulation	All versions	—	No fix listed	CNA

ModelSim Simulation VendorSiemens Affected All versions Fixed in — No fix listed CNA
Questa Simulation VendorSiemens Affected All versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:siemens:modelsim::::::::	all versions	Vulnerable	Siemens
cpe:2.3:a:siemens:questa::::::::	all versions	Vulnerable	Siemens

cpe:2.3:a:siemens:modelsim:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens
cpe:2.3:a:siemens:questa:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2021-42023
2026-10-03 Alias added: GHSA-x8jw-8x39-62fp

References

Patch 1

https://cert-portal.siemens.com/productcert/pdf/ssa-400332.pdf

TI-2024-36137 Uncontrolled search path in Siemens ModelSim CVSS 4.0MEDIUM 5.4
TI-2024-31562 Uncontrolled search path in Siemens ModelSim CVSS 4.0MEDIUM 5.4
TI-2024-31561 Uncontrolled search path in Siemens ModelSim CVSS 4.0MEDIUM 5.4
TI-2024-31560 Uncontrolled search path in Siemens ModelSim CVSS 4.0MEDIUM 5.4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences