CVE-2022-43750

What it actually does

A user-space client can write to usbmon's internal data structures in mon_bin.c, corrupting kernel memory and enabling further exploitation such as privilege escalation or denial of service.

Why it matters to the business

Local attackers with sufficient privileges can crash systems or gain elevated access on Linux hosts that expose usbmon, increasing downtime and risk of compromise in environments running older kernels.

How an attack unfolds

An attacker with local access opens the usbmon device, crafts malicious control messages that target internal buffers, triggers memory corruption, and leverages the resulting state to execute arbitrary code or elevate privileges.

How to fix it

Upgrade the Linux kernel to version 5.19.15 or newer, or 6.0.1 or newer; the fix is present in commit a659daf63d16aa883be42f3f34ff84235c302198.

How to confirm the fix worked

Confirm kernel version is at or above the fixed releases; check for presence of the referenced commit in the running kernel source; attempt to exercise usbmon interfaces under controlled conditions to verify no corruption occurs.

Typical attack path

1. Obtain local shell on target Linux system
2. Open /dev/usbmon or equivalent usbmon interface
3. Send specially crafted ioctl or write operations to mon_bin
4. Trigger memory corruption in kernel structures
5. Escalate privileges or cause kernel panic

How to detect it

Review kernel logs for usbmon-related oops or panic messages; inspect process activity opening usbmon character devices; correlate with unusual local privilege changes on affected hosts.

What your security team should do

• Prioritize kernel upgrades on all internet-facing or multi-user Linux systems
• Restrict access to usbmon devices via permissions or disable the module if not required
• Monitor EPSS and exploit availability; low current scores do not eliminate need for patching given 1452 days since disclosure