CVE-2024-43815

What it actually does

The flaw allows stack memory disclosure through an uninitialized payload field in the mxs-dcp AES descriptor when a hardware key slot is used instead of a memory-supplied key.

Why it matters to the business

Attackers may obtain fragments of kernel stack memory containing sensitive data such as keys or other process information; the issue affects the Linux kernel with 886 downstream dependents, increasing exposure across embedded and crypto-using systems.

How an attack unfolds

An attacker with the ability to trigger AES operations via the mxs-dcp driver using a hardware key slot can observe the leaked stack bytes returned in the payload field of the completed descriptor.

How to fix it

Update the Linux kernel to version 6.10.3 or later, or apply commit e1640fed0377bf7276efb70d03cb821a6931063d; for the cryptography PyPI package update to 41.0.2 or later.

How to confirm the fix worked

Confirm the presence of the zeroing of the payload field when a key slot is selected in the mxs-dcp driver source; verify the running kernel reports a fixed version string and test AES key-slot operations return a zeroed payload.

Typical attack path

1. Identify a system using the mxs-dcp crypto driver and hardware key slots for AES
2. Craft or trigger an AES operation that selects a key slot rather than supplying the key in memory
3. Inspect the returned descriptor payload for residual stack bytes
4. Extract and analyze any disclosed kernel memory contents

How to detect it

Review kernel logs and crypto driver traces for unexpected non-zero payload values during AES key-slot operations; examine process memory or core dumps for leaked stack artifacts originating from mxs-dcp descriptor handling.

What your security team should do

• Prioritize patching kernel packages on all systems using mxs-dcp hardware crypto
• Audit for use of hardware key slots in AES operations and prefer memory-supplied keys where possible until patched
• Monitor EPSS and KEV status for any future changes indicating increased exploitation risk