🟡 Medium | Source: Microsoft Security Response Center
CVE-2025-21870 is a vulnerability in the Linux kernel’s Audio over HDA (ALH) copier lookup loops within the Sound Open Firmware (SOF) IPC4 topology component. While categorised under Azure advisories via the Microsoft Security Response Center, this is a Linux kernel-level flaw that could affect Azure infrastructure or Linux-based virtual machines running affected kernel versions. The hardening of these loops suggests a potential out-of-bounds access or logic error that could be exploited to cause instability or unexpected behaviour.
Security Architect’s Take: Review whether your Azure Linux VMs or AKS node pools are running kernel versions affected by this CVE, and ensure OS-level patching is current. If you manage custom VM images, prioritise rebuilding them against a patched kernel and validate your patch compliance posture via Azure Policy or Defender for Cloud.
Original advisory: CVE-2025-21870 ASoC: SOF: ipc4-topology: Harden loops for looking up ALH copiers