CVE-2021-43975

What it actually does

Out-of-bounds write in the hw_atl_utils_fw_rpc_wait function of the Aquantia Atlantic Ethernet driver caused by a crafted length value supplied by a malicious device, resulting in kernel memory corruption.

Why it matters to the business

Enables local attackers with hardware access to achieve kernel-level code execution on affected Linux systems, risking full host compromise, data exposure, or persistence on servers and appliances using vulnerable Aquantia network hardware.

How an attack unfolds

An attacker introduces a crafted physical or virtual Aquantia device that responds to firmware RPC calls with an oversized length value; the driver writes attacker-controlled data beyond buffer bounds, corrupting kernel memory and enabling privilege escalation or arbitrary code execution.

How to fix it

Upgrade the Linux kernel to a version containing the fix for the Aquantia Atlantic driver bounds check; apply vendor firmware updates for affected NetApp storage systems and remove or disable vulnerable hardware where updates are unavailable.

How to confirm the fix worked

Confirm the presence of bounds validation in hw_atl_utils.c after the vulnerable length handling; test device attachment with synthetic malicious responses and verify absence of kernel panics or memory corruption indicators.

Typical attack path

1. Obtain physical or virtual access to introduce a malicious Aquantia Atlantic device
2. Trigger device enumeration and firmware RPC interaction
3. Supply crafted length value to hw_atl_utils_fw_rpc_wait
4. Perform out-of-bounds write to corrupt kernel memory structures
5. Leverage memory corruption for privilege escalation or code execution

How to detect it

Review kernel logs for atlantic driver crashes or oops messages during device initialization; inspect system logs for unexpected hardware attachment events or firmware RPC activity from untrusted devices.

What your security team should do

• Apply kernel updates immediately on all systems exposing Aquantia hardware
• Restrict physical and virtual device attachment privileges
• Audit and inventory systems using Aquantia Atlantic controllers
• Monitor EPSS trend and exploit availability for prioritization