CVE-2024-43390 Phoenix Contact: Firewall reconfiguration due to improper input validation in MGUARD devices

High 8.1 Published 10 Sep 2024 Updated 22 Aug 2025

A low-privileged remote attacker can inject code via environment variables to reconfigure firewall services, causing denial of service.

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

What is CVE-2024-43390?

CVE-2024-43390 is a high-severity code injection vulnerability in PHOENIX CONTACT FL MGUARD 2102, published on 10 Sep 2024. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A low privileged remote attacker can perform configuration changes of the firewall services, including packet forwarding or NAT through the FW_NAT.IN_IP environment variable which can lead to a DoS.

Weakness: CWE-94

Which versions are affected by CVE-2024-43390?

It affects 36 products.

Products include Phoenixcontact Fl Mguard 2102 Firmware, Phoenixcontact Fl Mguard 2105 Firmware, Phoenixcontact Fl Mguard 4102 Pci Firmware, Phoenixcontact Fl Mguard 4102 Pcie Firmware, Phoenixcontact Fl Mguard 4302 Firmware, Phoenixcontact Fl Mguard 4305 Firmware and 30 more.

How do I fix CVE-2024-43390?

No fix has been published for CVE-2024-43390 yet. Limit exposure of the affected software until one is available.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2024-43390 being exploited?

There is no known exploitation of CVE-2024-43390 in the wild and no public exploit code.

Sources

Also known as GHSA-vw69-gxfr-pfgr.