CVE-2026-90647 Kalkitech CVE debrief

Who should care

Defenders responsible for ASE/Kalkitech ASE2000 V2 Communication Test Set versions 2.35 through 2.37 on Windows should assess exposure and prioritize verification and remediation efforts.

Why it matters

Defenders should prioritize verifying and updating ASE2000 V2 Communication Test Set versions 2.35 through 2.37, implementing robust certificate validation, and monitoring for potential Man-in-the-Middle attacks due to the critical vulnerability allowing certificate bypass and potential exposure.

• Potential for Man-in-the-Middle attacks on protected communications.
• Bypass of certificate validation in IEC 60870-5-104 TLS client (Task Mode).
• Exposure of ASE/Kalkitech ASE2000 V2 Communication Test Set versions 2.35 through 2.37 on Windows.

Technical summary

The IEC 60870-5-104 TLS client (Task Mode) in ASE/Kalkitech ASE2000 V2 Communication Test Set versions 2.35 through 2.37 on Windows improperly validates certificates. This allows a network-positioned attacker to bypass certificate validation using a certificate with multiple simultaneous faults, enabling a Man-in-the-Middle attack on protected communications. Defenders should prioritize verifying and updating ASE2000 V2 Communication Test Set versions 2.35 through 2.37, implementing robust certificate validation, and monitoring for potential Man-in-the-Middle attacks. The vulnerability is confirmed in ASE/Kalkitech ASE2000 V2 Communication Test Set versions 2.35 through 2.37 on Windows.

Defensive priority

Defenders should prioritize verifying and updating ASE2000 V2 Communication Test Set versions 2.35 through 2.37, implementing robust certificate validation, and monitoring for potential Man-in-the-Middle attacks.

Recommended defensive actions

• Verify and update ASE2000 V2 Communication Test Set versions 2.35 through 2.37 to ensure robust certificate validation.
• Implement monitoring to detect potential Man-in-the-Middle attacks on protected communications.
• Review and enhance network positioning to prevent attackers from exploiting the vulnerability.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability is confirmed in ASE/Kalkitech ASE2000 V2 Communication Test Set versions 2.35 through 2.37 on Windows. The IEC 60870-5-104 TLS client (Task Mode) is affected by improper certificate validation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.