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Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVE-2021-21005

High
7.5/10

Summary

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.

  • LOW
  • NETWORK
  • NONE
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • HIGH

CWE-362 - Race Condition

A race condition occurs in a shared memory program when two threads/processes access the same shared memory data, and at least one thread executes a write operation. This vulnerability manipulates the time to check vs. time to use (TOC/TOU) gap between the threads in the critical section to cause disorientation in the shared data. The impact can vary from compromising the confidentiality of the system to causing the system to crash or to execute arbitrary code.

References

Advisory Timeline

  • Published