CVE-2021-21005

Race Condition Vulnerability in Phoenix Contact FL SWITCH SMCS series products

Description

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.

Remediation

Workaround:

  • Phoenix Contact recommends operating network-capable devices in closed networks or protected with a suitable firewall. For detailed information on our recommendations for measures to protect network-capable devices, please refer to the Phoenix Contact application note: Measures to protect network-capable devices with Ethernet connection https://dam-mdc.phoenixcontact.com/asset/156443151564/0a870ae433c19148b80bd760f3a1c1f2/107913_en_03.pdf

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.04%
Third-Party Advisory vde.com
Affected: Phoenix Contact FL SWITCH
Affected: Phoenix Contact FL NAT
Published at:
Updated at:

References

Link Tags
https://cert.vde.com/en-us/advisories/vde-2021-023 third party advisory

Frequently Asked Questions

What is the severity of CVE-2021-21005?
CVE-2021-21005 has been scored as a high severity vulnerability.
How to fix CVE-2021-21005?
As a workaround for remediating CVE-2021-21005: Phoenix Contact recommends operating network-capable devices in closed networks or protected with a suitable firewall. For detailed information on our recommendations for measures to protect network-capable devices, please refer to the Phoenix Contact application note: Measures to protect network-capable devices with Ethernet connection https://dam-mdc.phoenixcontact.com/asset/156443151564/0a870ae433c19148b80bd760f3a1c1f2/107913_en_03.pdf
Is CVE-2021-21005 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-21005 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-21005?
CVE-2021-21005 affects Phoenix Contact FL SWITCH, Phoenix Contact FL NAT.
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