CVE-2020-7549 Denial of service in Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions)

High 7.5 Published Updated

Attackers can cause denial of HTTP and FTP services on Modicon PLCs by sending specially crafted requests to the web server.

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-2020-7549?

CVE-2020-7549 is a high-severity denial of service vulnerability in Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions), published on 11 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists in the Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions), that could cause denial of HTTP and FTP services when a series of specially crafted requests is sent to the controller over HTTP.

Weakness: CWE-754

Which versions are affected by CVE-2020-7549?

It affects 19 products.

Products include Schneider-Electric 140cpu65150 Firmware, Schneider-Electric 140noc78000 Firmware, Schneider-Electric 140noc78100 Firmware, Schneider-Electric 140noe77111 Firmware, Schneider-Electric Bmxnoc0401 Firmware, Schneider-Electric Bmxnoe0100 Firmware and 13 more.

How do I fix CVE-2020-7549?

No fix has been published for CVE-2020-7549 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2020-7549 being exploited?

There is no known exploitation of CVE-2020-7549 in the wild and no public exploit code.

Sources

Also known as GHSA-mg3m-w94w-vr47.

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