high
7.8
CWE
362
Advisory Published
Updated

CVE-2021-21005: Race Condition Vulnerability in Phoenix Contact FL SWITCH SMCS series products

First published: Fri Jun 25 2021(Updated: )

In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.

Credit: info@cert.vde.com

Affected SoftwareAffected VersionHow to fix
Phoenixcontact FL Switch SMCS 16TX Firmware<=4.70
Phoenix Contact FL Switch SMCS 16TX
Phoenixcontact Fl Switch Smcs 14tx/2fx Firmware<=4.70
Phoenixcontact Fl Switch Smcs 14tx/2fx
Phoenixcontact Fl Switch Smcs 14tx/2fx-sm Firmware<=4.70
Phoenix Contact FL Switch SMCS 14TX/2FX-SM
Phoenix Contact FL Switch SMCS 8GT Firmware<=4.70
Phoenixcontact Fl Switch Smcs 8gt Firmware
Phoenixcontact Fl Switch Smcs 6gt/2sfp Firmware<=4.70
Phoenixcontact Fl Switch Smcs 6gt/2sfp
Phoenixcontact Fl Switch Smn 8tx-pn Firmware<=4.70
Phoenixcontact Fl Switch Smcs 8tx-pn Firmware
Phoenix Contact FL Switch SMCS 4TX-PN Firmware<=4.70
Phoenix Contact FL Switch SMCS 4TX-PN Firmware
Phoenixcontact Fl Switch Smcs 8tx Firmware<=4.70
Phoenix Contact FL Switch SMCS 8TX
Phoenixcontact Fl Switch Smcs 6tx/2sfp Firmware<=4.70
Phoenixcontact Fl Switch Smcs 6tx/2sfp
Phoenix Contact FL Switch SMN 6TX/2POF-PN Firmware<=4.70
Phoenix Contact FL Switch SMN 6TX/2POF-PN
Phoenix Contact FL Switch SMN 8TX-PN Firmware<=4.70
Phoenixcontact Fl Switch Smn 8tx-pn Firmware
Phoenixcontact Fl Switch Smn 6tx/2fx Firmware<=4.70
Phoenixcontact Fl Switch Smn 6tx/2fx
Phoenixcontact Fl Switch Smn 6tx/2fx Sm Firmware<=4.70
Phoenix Contact FL Switch SMN 6TX/2FX SM
Phoenix Contact FL NAT SMN 8TX Firmware<=4.63
Phoenix Contact FL NAT SMN 8TX-M
Phoenix Contact FL NAT SMN 8TX-M Firmware<=4.63
Phoenix Contact FL NAT SMN 8TX-M Firmware

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Reference Links

Frequently Asked Questions

  • What is the vulnerability ID for this issue?

    The vulnerability ID for this issue is CVE-2021-21005.

  • What is the severity of CVE-2021-21005?

    CVE-2021-21005 has a severity of 7.5 (High).

  • Which products are affected by CVE-2021-21005?

    Phoenix Contact FL SWITCH SMCS series products in multiple versions are affected.

  • How does the vulnerability in CVE-2021-21005 exploit the network stack?

    An attacker can crash the network stack by sending a hand-crafted TCP packet with the Urgent-Flag set and the Urgent-Pointer set to 0.

  • What is the recommended action to fix CVE-2021-21005?

    To fix CVE-2021-21005, the affected device needs to be rebooted.

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