A security vulnerability in AMD’s Secure Encrypted Virtualization (SEV) has been disclosed, allowing an attacker with local administrator privileges to load malicious CPU microcode. The flaw, tracked as CVE-2024-56161, carries a CVSS score of 7.2 out of 10.0, indicating high severity.
According to AMD, the vulnerability arises from improper signature verification in the SEV patch loader, which could result in loss of confidentiality and integrity for confidential guest VMs running under SEV-SNP. Google security researchers Josh Eads, Kristoffer Janke, Eduardo Vela, Tavis Ormandy, and Matteo Rizzo discovered and reported the flaw on September 25, 2024.
SEV is a security feature that isolates virtual machines from each other using unique keys. SNP provides memory integrity protections to safeguard against hypervisor-based attacks. However, the new vulnerability could be exploited by compromising confidential computing workloads.
Google has released a test payload demonstrating the vulnerability and plans to release additional technical details in another month to allow fixes to propagate through the supply chain.
Source: https://thehackernews.com/2025/02/amd-sev-snp-vulnerability-allows.html