CVE-2024-46825

What it actually does

The lookup function iwl_mvm_rcu_fw_link_id_to_link_conf() performed insufficient validation on link IDs supplied by firmware, using a debug-only WARN_ON() assertion instead of the production-grade IWL_FW_CHECK() macro, allowing malformed or unexpected firmware input to proceed without proper error handling.

Why it matters to the business

Organizations running affected Linux kernels on Intel wireless hardware face elevated risk of driver instability or unexpected behavior triggered by firmware-supplied data; the large number of downstream dependents increases exposure across server and endpoint fleets, with urgency driven by the age of the issue and ongoing exploitation activity by espionage and financially motivated actors.

How an attack unfolds

An attacker supplies crafted firmware responses or triggers conditions that cause the link ID lookup to receive invalid input; the weak WARN_ON() check fails to halt execution, permitting the kernel to continue with unvalidated data that can be leveraged for further abuse in campaigns by named threat actors.

How to fix it

Update to a fixed kernel commit such as 415f3634d53c7fb4cf07d2f5a0be7f2e15e6da33 or later stable releases containing the IWL_FW_CHECK change; for dependent packages such as caddy update to version 0.10.13 or newer that incorporate the corrected kernel components.

How to confirm the fix worked

Confirm the running kernel contains commit 415f3634d53c7fb4cf07d2f5a0be7f2e15e6da33 or equivalent, verify the source contains IWL_FW_CHECK() in the link ID lookup path, and test that invalid firmware link IDs now trigger the hardened check without proceeding.

Typical attack path

1. Identify systems with vulnerable iwlwifi driver versions
2. Trigger or intercept firmware communication paths to supply malformed link IDs
3. Bypass the insufficient WARN_ON() check to reach downstream code paths
4. Leverage resulting state for privilege escalation or persistence

How to detect it

Review kernel logs and dmesg output for WARN_ON() messages or link ID related assertions originating from iwl_mvm; correlate with firmware interaction events and monitor for post-exploitation artifacts associated with the listed threat actor campaigns.

What your security team should do

• Prioritize patching all affected kernel packages within the CISA-recommended window if applicable
• Monitor EPSS trend and threat actor activity for any increase in targeting of Linux wireless drivers
• Audit wireless hardware deployments for unpatched systems given the high ecosystem prevalence
• Incorporate kernel version checks into vulnerability scanning and asset inventory processes