CVE-2019-8922

What it actually does

Heap-based buffer overflow in service_attr_req called by process_request due to unconditional appending of attribute values into a preallocated response buffer with no size validation.

Why it matters to the business

Remote code execution or service crash on Bluetooth-enabled systems; high operational risk for any device using the affected Bluetooth stack given public exploit availability and 1773 days since disclosure.

How an attack unfolds

An attacker on the local Bluetooth network sends a crafted SDP service attribute request; the daemon allocates a response buffer then appends all returned attribute data without bounds checks, overflowing the heap and enabling code execution or denial of service.

How to fix it

Upgrade grpc/grpc-swift to commit 858f977f2a51fca2292f384cf7a108dc2e73a3bd; apply equivalent patches or updates for any BlueZ installations still at or below version 5.48.

How to confirm the fix worked

Confirm the commit or package version matches the fixed revision; recompile and test SDP attribute requests to verify buffer-size checks are present and no overflow occurs.

Typical attack path

1. Establish SDP connection to target Bluetooth daemon
2. Send malicious service_attr_req with oversized attribute data
3. Trigger uncontrolled append into undersized response buffer
4. Achieve heap corruption leading to RCE or crash

How to detect it

Review Bluetooth daemon logs and system crash reports for heap corruption indicators around SDP request handling; look for repeated large attribute responses or sudden bluetoothd restarts.

What your security team should do

• Prioritize patching all instances of the affected Bluetooth stack or grpc-swift dependency within 48 hours
• Disable SDP service if not required
• Monitor for anomalous Bluetooth traffic and heap-related crashes
• Review downstream dependents for similar exposure given ecosystem prevalence