CVE-2021-22786 Information disclosure in Legacy Modicon Quantum

High 7.5 Published 1 Feb 2023 Updated 5 Feb 2025

Attackers can expose sensitive memory information from Modicon PLCs via Modbus TCP, requiring firmware upgrades for mitigation.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-22786?

CVE-2021-22786 is a high-severity vulnerability in Schneider Electric Legacy Modicon Quantum, published on 1 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A CWE-200: Information Exposure vulnerability exists that could cause the exposure of sensitive information stored on the memory of the controller when communicating over the Modbus TCP protocol. Affected Products: Modicon M340 CPU (part numbers BMXP34*) (Versions prior to V3.30), Modicon M580 CPU (part numbers BMEP* and BMEH*) (Versions prior to SV3.20), Modicon MC80 (BMKC80) (Versions prior to V1.6), Modicon M580 CPU Safety (part numbers BMEP58*S and BMEH58*S) (All Versions), Modicon Momentum MDI (171CBU*) (Versions prior to V2.3), Legacy Modicon Quantum (All Versions)

Weakness: CWE-200

Which versions are affected by CVE-2021-22786?

It affects 41 products.

Products include Schneider-Electric Modicon M340 Bmxp341000 Firmware, Schneider-Electric Modicon M340 Bmxp342000 Firmware, Schneider-Electric Modicon M340 Bmxp3420102 Firmware, Schneider-Electric Modicon M340 Bmxp342010 Firmware, Schneider-Electric Modicon M340 Bmxp342020 Firmware, Schneider-Electric Modicon M340 Bmxp342020h Firmware and 35 more.

How do I fix CVE-2021-22786?

No fix has been published for CVE-2021-22786 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-22786 being exploited?

There is no known exploitation of CVE-2021-22786 in the wild and no public exploit code.

Sources

Also known as GHSA-c8j6-69w9-74h6.