CVE-2025-54510: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-54510 is a missing lock verification vulnerability in AMD Secure Processor (ASP) firmware, tracked under AMD Security Bulletin AMD-SB-3034 and named "FabricKed" by researchers. It affects AMD EPYC 7003, 8004, 9004, and 9005 Series Processors (including Embedded variants) running on Zen 5-based platforms, specifically impacting SEV-SNP (Secure Encrypted Virtualization – Secure Nested Paging) configurations. The vulnerability was disclosed on April 14, 2026, with patches having been released between November 2025 and April 2026. It carries a CVSS v4.0 base score of 5.9 (Medium) (AMD Advisory, GitHub Advisory).

The root cause is classified as CWE-414 (Missing Lock Check): the AMD Secure Processor firmware fails to verify the presence of a lock before allowing modifications to Memory-Mapped I/O (MMIO) routing. An attacker with local administrative privileges can exploit this flaw to alter MMIO routing on affected Zen 5-based systems, bypassing the integrity protections provided by SEV-SNP. The attack requires no user interaction and no special attack requirements beyond high privilege level, making it a local, low-complexity exploit once administrative access is obtained. The vulnerability specifically affects SEV-SNP (not SEV or SEV-ES), as confirmed in AMD's bulletin (AMD Advisory). Researchers from ETH Zurich (Benedict Schluter, Christoph Wech, and Shweta Shinde) discovered and reported the issue, and published technical details under the "FabricKed" name (FabricKed Research).

Successful exploitation allows a privileged local attacker to alter MMIO routing on affected AMD EPYC processors, compromising the integrity of guest virtual machines protected by SEV-SNP. In cloud and virtualized environments, this means a malicious or compromised hypervisor/host administrator could potentially read confidential VM memory and forge SEV-SNP attestation reports, undermining the hardware-based trust guarantees that tenants rely upon. The CVSS v4.0 scoring reflects high integrity impact on subsequent (guest) systems, with no direct confidentiality or availability impact on the vulnerable system itself (AMD Advisory, GitHub Advisory).

There is no public proof-of-concept exploit code and no evidence of in-the-wild exploitation at this time (GitHub Advisory). The EPSS score is approximately 0.012–0.017%, placing it in the 4th percentile for exploitation likelihood within 30 days. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires local administrative privileges, significantly limiting the attacker pool to insiders or already-compromised privileged accounts. The vulnerability has been detected by Nessus (plugin ID 307591) (Tenable).

1. Gain Administrative Access: Obtain local administrative (root/hypervisor-level) access to a system running an affected AMD EPYC processor (7003, 8004, 9004, or 9005 series) with SEV-SNP enabled and unpatched ASP firmware.
2. Identify Vulnerable Firmware: Confirm the system is running a vulnerable Platform Initialization (PI) version (e.g., MilanPI prior to 1.0.0.J, GenoaPI prior to 1.0.0.H, TurinPI prior to 1.0.0.8) using system management tools or BIOS version checks.
3. Exploit Missing Lock Check: Leverage the missing lock verification in the ASP firmware to issue commands that modify MMIO routing without the expected lock enforcement, bypassing SEV-SNP's integrity protections.
4. Alter MMIO Routing: Redirect MMIO mappings to gain unauthorized access to guest VM memory regions or manipulate data visible to SEV-SNP-protected guests.
5. Compromise Guest Integrity / Forge Attestation: Read confidential guest VM memory or manipulate attestation reports to forge SEV-SNP attestation, undermining tenant trust in the hardware security boundary (AMD Advisory, FabricKed Research).

• Firmware/Configuration: ASP/PI firmware versions below the patched thresholds (MilanPI < 1.0.0.J, GenoaPI < 1.0.0.H, TurinPI < 1.0.0.8, EmbMilanPI-SP3 < 1.0.0.D, EmbGenoaPI-SP5 < 1.0.0.D, EmbeddedTurinPI_SP5 < 1004); TCB[SNP] values below the mitigated thresholds (e.g., TCB[SNP] < 0x1D for EPYC 7003, < 0x1C for 8004/9004, < 0x5 for 9005).
• Attestation: Unexpected or anomalous SEV-SNP attestation reports; attestation TCB values not reflecting patched firmware levels, which may indicate forged or manipulated attestation.
• System Logs: Unusual administrative activity on hypervisor or host OS related to MMIO configuration or firmware management interfaces; unexpected BIOS/firmware update attempts or rollbacks.
• Network: Anomalous outbound data transfers from cloud host nodes that could indicate exfiltration of guest VM memory contents.

AMD has released patched Platform Initialization (PI) firmware versions for all affected processor families. Users should apply the following updates via OEM-provided BIOS updates: MilanPI-SP3 1.0.0.J (EPYC 7003, released 2025-12-02), GenoaPI 1.0.0.H (EPYC 8004 and 9004, released 2025-12-15), TurinPI 1.0.0.8 (EPYC 9005, released 2025-11-26), EmbMilanPI-SP3 1.0.0.D (Embedded 7003, released 2026-01-02), EmbGenoaPI-SP5 1.0.0.D (Embedded 8004 and 9004, released 2026-02-02), and EmbeddedTurinPI_SP5_1004 (Embedded 9005, released 2026-04-13). Organizations should contact their OEM for the specific BIOS update applicable to their hardware, restrict administrative access to authorized personnel only, and verify SEV-SNP attestation TCB values meet the mitigated thresholds (AMD Advisory).

The vulnerability was discovered and reported by researchers Benedict Schluter, Christoph Wech, and Shweta Shinde of ETH Zurich, who named it "FabricKed" and published a dedicated research site (FabricKed Research). Coverage appeared in Tom's Hardware, which described the attack as allowing malicious cloud hosts to silently read confidential VM memory and forge attestation reports (Tom's Hardware). Security outlets including SecurityOnline and Red Hot Cyber also covered the disclosure, highlighting the cloud security implications for AMD SEV-SNP-protected workloads (SecurityOnline). Dell and HPE issued their own security advisories referencing this CVE for affected PowerEdge and other AMD-based server products.