CVE-2022-42895

What it actually does

The vulnerability allows remote disclosure of kernel memory pointers through malformed L2CAP configuration request packets processed in l2cap_parse_conf_req.

Why it matters to the business

Organizations running Linux systems with Bluetooth enabled face increased risk of targeted kernel memory disclosure from nearby attackers, potentially aiding further kernel exploitation and system compromise.

How an attack unfolds

An attacker within Bluetooth range crafts and sends a malicious L2CAP configuration request to a vulnerable Linux device; the kernel's l2cap_parse_conf_req function leaks internal pointers in the response, which the attacker can use to prepare subsequent memory corruption attacks.

How to fix it

Upgrade the Linux kernel to include commit b1a2cd50c0357f243b7435a732b4e62ba3157a2e or later; disable Bluetooth when not required.

How to confirm the fix worked

Verify the running kernel contains commit b1a2cd50c0357f243b7435a732b4e62ba3157a2e; test by sending L2CAP config requests and confirming absence of pointer disclosure in responses.

Typical attack path

1. Establish adjacency via Bluetooth with target Linux system
2. Send specially crafted L2CAP configuration request packet
3. Receive response containing leaked kernel pointers
4. Use disclosed pointers to craft follow-on kernel exploits

How to detect it

Inspect Bluetooth packet captures and kernel logs for anomalous L2CAP configuration requests; correlate with any subsequent memory corruption attempts or unexpected kernel pointer references in crash dumps.

What your security team should do

• Apply the referenced kernel commit immediately on all Bluetooth-enabled Linux systems
• Disable Bluetooth interfaces by default via kernel configuration or runtime controls
• Monitor for new kernel releases containing the fix and schedule patching
• Review Bluetooth usage policies to reduce attack surface