CVE-2020-7536 Denial of service in Modicon M340 CPUs (BMXP34* versions prior to V3.30) and Modicon M340 Communication Ethernet modules (BMXNOE0100 (H) versions prior to V3.4, BMXNOE0110 (H) versions prior to V6.6, and BMXNOR0200H all versions)
Attackers can render Modicon M340 devices unreachable by modifying network parameters via SNMP, causing a denial of service.
- 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-2020-7536?
CVE-2020-7536 is a high-severity denial of service vulnerability in Modicon M340 CPUs (BMXP34* versions prior to V3.30) and Modicon M340 Communication Ethernet modules (BMXNOE0100 (H) versions prior to V3.4, BMXNOE0110 (H) versions prior to V6.6, and BMXNOR0200H all 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 Modicon M340 CPUs (BMXP34* versions prior to V3.30) Modicon M340 Communication Ethernet modules (BMXNOE0100 (H) versions prior to V3.4 BMXNOE0110 (H) versions prior to V6.6 BMXNOR0200H all versions), that could cause the device to be unreachable when modifying network parameters over SNMP.
Weakness: CWE-754
Which versions are affected by CVE-2020-7536?
It affects 10 products.
Products include Schneider-Electric Bmxnoe0100 Firmware, Schneider-Electric Bmxnoe0110 Firmware, Schneider-Electric Bmxnor0200h Firmware, Schneider-Electric Modicon M340 Bmxp341000 Firmware, Schneider-Electric Modicon M340 Bmxp342000 Firmware, Schneider-Electric Modicon M340 Bmxp3420102 Firmware and 4 more.
How do I fix CVE-2020-7536?
No fix has been published for CVE-2020-7536 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-2020-7536 being exploited?
There is no known exploitation of CVE-2020-7536 in the wild and no public exploit code.
Other vulnerabilities in Modicon M340 CPUs (BMXP34* versions prior to V3.30) and Modicon M340 Communication Ethernet modules (BMXNOE0100 (H) versions prior to V3.4, BMXNOE0110 (H) versions prior to V6.6, and BMXNOR0200H all versions)
Sources
Also known as GHSA-7f68-748r-v7xr.