CVE-2025-54509 Overview
CVE-2025-54509 is an improper access control vulnerability [CWE-1262] in the register interface of the AMD input-output memory management unit (IOMMU). A privileged local attacker can manipulate the exposed register interface to cause non-coherent memory accesses by the AMD secure processor (ASP). The resulting cache and memory state inconsistencies undermine the integrity guarantees that the ASP relies on for protected operations. AMD documented the issue in AMD Security Bulletin #3039. Exploitation requires local access with high privileges, and no public exploit code is currently available.
Critical Impact
A privileged local attacker can induce non-coherent ASP accesses, breaking integrity assumptions of the AMD secure processor trust boundary.
Affected Products
- AMD processors exposing the affected IOMMU register interface (see AMD Security Bulletin #3039 for the authoritative product list)
- AMD secure processor (ASP) firmware components dependent on IOMMU coherency
- Platforms relying on the ASP for confidential or integrity-sensitive workloads
Discovery Timeline
- 2026-06-09 - CVE CVE-2025-54509 published to NVD
- 2026-06-09 - Last updated in NVD database
Technical Details for CVE-2025-54509
Vulnerability Analysis
The flaw resides in how the IOMMU exposes its register interface to privileged software. Access controls on these registers are insufficient to prevent a privileged caller from configuring the IOMMU in a way that produces non-coherent memory transactions for the AMD secure processor. The ASP performs sensitive operations under the assumption that its view of memory is coherent with the rest of the platform. When that assumption breaks, attacker-controlled memory state can diverge from what the ASP observes, enabling integrity violations in security-critical paths.
The vulnerability is local and requires high privileges, which limits remote exploitation but is relevant for multi-tenant hosts, virtualization platforms, and supply chain scenarios where ring-0 access may already be obtained through another defect.
Root Cause
The root cause is improper access control on a hardware register interface, classified under [CWE-1262] (improper access control for register interface). The IOMMU does not adequately restrict which privileged entities may configure coherency-relevant settings, allowing a caller to drive the ASP into a non-coherent access pattern.
Attack Vector
Exploitation requires local execution at a high privilege level, such as kernel or hypervisor context. The attacker programs the IOMMU through its exposed register interface to manipulate DMA or memory mapping behavior in a way that the ASP processes non-coherent data. The result is a loss of integrity for ASP-mediated operations. No proof-of-concept code, exploit, or in-the-wild activity has been reported, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog.
No verified exploitation code is publicly available. Refer to AMD Security Bulletin #3039 for vendor-supplied technical details.
Detection Methods for CVE-2025-54509
Indicators of Compromise
- No public indicators of compromise have been published for CVE-2025-54509.
- Unexpected ASP errors, attestation failures, or secure boot integrity warnings on affected AMD platforms may warrant further investigation.
- Anomalous kernel or hypervisor-level access to IOMMU MMIO regions outside expected platform firmware activity.
Detection Strategies
- Monitor for unauthorized kernel modules or drivers that access IOMMU configuration registers.
- Correlate platform firmware logs and ASP attestation reports to identify integrity anomalies.
- Track privileged process activity that interacts with /dev/mem, MMIO mappings, or IOMMU-related sysfs entries on Linux hosts.
Monitoring Recommendations
- Enable and centralize platform firmware and hypervisor logs that record IOMMU configuration changes.
- Audit driver and kernel module load events on hosts that handle sensitive workloads dependent on the ASP.
- Alert on attestation verification failures from systems that rely on AMD secure processor measurements.
How to Mitigate CVE-2025-54509
Immediate Actions Required
- Identify AMD-based systems referenced in AMD Security Bulletin #3039 and prioritize them for firmware updates.
- Restrict local administrative and hypervisor access on affected hosts to trusted operators only.
- Validate the integrity of platform firmware and ASP measurements where remote attestation is in use.
Patch Information
AMD has published AMD Security Bulletin #3039 covering CVE-2025-54509. Consult that advisory for the authoritative list of impacted processors and the corresponding AGESA or platform firmware versions that contain the fix. Apply vendor BIOS/UEFI updates from the system OEM once they integrate the patched AGESA release.
Workarounds
- No vendor-provided workarounds have been published; firmware updates are the recommended remediation.
- Reduce risk by hardening privileged access controls and minimizing the number of administrators capable of loading kernel-mode code.
- For multi-tenant environments, restrict guest privileges and disable direct device assignment where ASP integrity is required.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
