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Loop with Unreachable Exit Condition ('Infinite Loop')

CVE-2021-28484

High
7.5/10

Summary

An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.

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

CWE-835 - Loop with Unreachable Exit Condition

Loops with multiple exits and flags detract from the quality of an application. They tend to make control structures difficult to understand, and introduce the risk of non-termination and other structural problems. The vulnerability “loop with unreachable exit condition” enables attackers to exploit this flaw, leading to denial of service.

References

Advisory Timeline

  • Published