CVE intelligence and bounded remediation

CVE-2021-31611 — Zh-Jieli Ac6901 Firmware security vulnerability

Medium CVSS 5.7

The Bluetooth Classic implementation on Zhuhai Jieli AC690X and AC692X devices does not properly handle an out-of-order LMP Setup procedure that is followed by a malformed LMP packet, allowing attackers in radio range to deadlock a device via a crafted LMP packet. The user needs to manually reboot the device to restore communication.

Severity
Medium
CVSS
5.7 (3.1)
Published
2021-09-07
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-667

Affected products

  • zh-jieli / ac6901_firmware
  • zh-jieli / ac6925_firmware
  • zh-jieli / ac6926_firmware
  • zh-jieli / ac6928_firmware
  • zh-jieli / ac6921_firmware

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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