CVE-2018-7846 Auth bypass in Modicon M580 Modicon M340 Modicon Quantum Modicon Premium

Critical 9.8 Published 22 May 2019 Updated 5 Aug 2024

Attackers can gain unauthorized access to Modicon PLCs via brute force attacks on the Modbus protocol, potentially leading to privilege escalation and data exposure.

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-2018-7846?

CVE-2018-7846 is a critical authentication bypass vulnerability in Modicon M580 Modicon M340 Modicon Quantum Modicon Premium, published on 22 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A CWE-501: Trust Boundary Violation vulnerability on connection to the Controller exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum and Modicon Premium which could cause unauthorized access by conducting a brute force attack on Modbus protocol to the controller.

Weakness: CWE-668

Which versions are affected by CVE-2018-7846?

It affects 4 products.

Products include Schneider-Electric Modicon M340 Firmware, Schneider-Electric Modicon M580 Firmware, Schneider-Electric Modicon Premium Firmware, Schneider-Electric Modicon Quantum Firmware.

How do I fix CVE-2018-7846?

No fix has been published for CVE-2018-7846 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2018-7846 being exploited?

There is no known exploitation of CVE-2018-7846 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Sources

Also known as GHSA-hvj5-x43r-qg3f.