CVE-2021-21003: Phoenixcontact Fl Nat Smn 8tx-M Firmware

Medium severity, CVSS 5.3. EPSS: 0.9% chance of exploitation in the next 30 days.

In Phoenix Contact FL SWITCH SMCS series products in multiple versions fragmented TCP-Packets may cause a Denial of Service of Web-, SNMP- and ICMP-Echo services. The switching functionality of the device is not affected.

Affected products

• Phoenixcontact Fl Nat Smn 8tx-M Firmware: up to and including 4.63
• Phoenixcontact Fl Nat Smn 8tx Firmware: up to and including 4.63
• Phoenixcontact Fl Switch Smcs 14tx/2fx-Sm Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 14tx/2fx Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 16tx Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 4tx-Pn Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 6gt/2sfp Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 6tx/2sfp Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 8gt Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 8tx-Pn Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smcs 8tx Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smn 6tx/2fx Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smn 6tx/2fx Sm Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smn 6tx/2pof-Pn Firmware: up to and including 4.70
• Phoenixcontact Fl Switch Smn 8tx-Pn Firmware: up to and including 4.70

Published 2021-06-25. Last modified 2026-06-17.