CVE-2025-48521: AMD Secure Processor UAF Vulnerability

CVE-2025-48521 Overview

CVE-2025-48521 is a Use-After-Free (UAF) vulnerability in the AMD Secure Processor (ASP) PCI driver. Improper input validation in the driver allows a local authenticated attacker to trigger memory reuse after deallocation. Successful exploitation can compromise platform integrity or cause a system crash.

The vulnerability is tracked under CWE-416: Use After Free. AMD has documented the issue in security bulletins AMD-SB-3047 and AMD-SB-4015. No public proof-of-concept code or active exploitation has been reported.

Critical Impact

A local attacker with low privileges can trigger memory corruption in the ASP PCI driver, leading to loss of platform integrity or denial of service through system crash.

Affected Products

• AMD Secure Processor (ASP) PCI driver
• AMD platforms referenced in AMD Security Bulletin SB-3047
• AMD platforms referenced in AMD Security Bulletin SB-4015

Discovery Timeline

• 2026-05-15 - CVE-2025-48521 published to NVD
• 2026-05-15 - Last updated in NVD database

Technical Details for CVE-2025-48521

Vulnerability Analysis

The flaw resides in the AMD Secure Processor PCI driver, a privileged component that interfaces with the dedicated security coprocessor on AMD platforms. The driver fails to properly validate input before operating on memory objects. This validation gap creates a window where a memory object can be freed while a reference to it remains reachable.

When subsequent code dereferences the stale pointer, the driver operates on memory that has been deallocated or reallocated. An attacker who controls the layout of freed memory can influence what data the driver consumes after the free. The resulting Use-After-Free condition [CWE-416] enables corruption of kernel-managed structures associated with ASP communication.

Because the ASP mediates trusted security operations including cryptographic services, secure boot validation, and platform attestation, corruption inside its driver path can undermine integrity guarantees the processor is intended to provide.

Root Cause

The root cause is improper input validation in code paths that manage allocated objects within the ASP PCI driver. Insufficient checks on lifecycle state allow object reuse after release, violating the memory safety invariants required for kernel-mode drivers.

Attack Vector

Exploitation requires local access and low-privilege authentication on the target system. An attacker invokes driver interfaces from user space with crafted input sequences that race or manipulate object lifecycle handling. No user interaction is required. The attack does not traverse the network and is constrained to the local machine.

The vulnerability is described in prose because no verified exploitation code is publicly available. Refer to AMD-SB-3047 and AMD-SB-4015 for vendor technical details.

Detection Methods for CVE-2025-48521

Indicators of Compromise

• Unexpected system crashes or bug checks referencing the ASP or AMD Secure Processor driver module
• Kernel logs showing memory access violations or pool corruption events tied to ASP PCI driver routines
• Repeated low-privilege process invocations of ASP driver IOCTLs in short time windows

Detection Strategies

• Monitor kernel crash dumps and OS event logs for faults attributed to the ASP PCI driver
• Correlate driver load events with subsequent privileged operations from low-integrity processes
• Apply integrity baselines to AMD driver binaries and alert on unexpected changes or downgrade attempts

Monitoring Recommendations

• Collect Windows WHEA, Linux kernel ring buffer, and dmesg output centrally for analysis of driver-level faults
• Track CPU vendor and driver version inventory across endpoints to identify unpatched AMD systems
• Alert on repeated kernel panics or blue screens on AMD hardware that share a common driver call signature

How to Mitigate CVE-2025-48521

Immediate Actions Required

• Apply firmware and driver updates referenced in AMD-SB-3047 and AMD-SB-4015 as supplied by your OEM
• Inventory AMD-based endpoints and servers to identify systems running vulnerable ASP PCI driver versions
• Restrict local interactive and remote shell access on affected systems to trusted administrators only

Patch Information

AMD has published guidance through security bulletins SB-3047 and SB-4015. Customers should obtain updated platform firmware, chipset drivers, and ASP driver packages from their system OEM or AMD support channels. Validate patch deployment by confirming the driver and firmware versions specified in the AMD bulletins.

Workarounds

• Limit local logon rights and enforce least privilege for accounts on affected AMD systems until patches are applied
• Disable or restrict access to ASP driver interfaces in environments where the secure processor functionality is not required, where supported by the OS and vendor
• Apply application allowlisting to prevent untrusted local binaries from invoking driver IOCTLs

# Example: identify AMD ASP driver presence on Linux
lsmod | grep -i ccp
modinfo ccp | grep -E 'version|filename'

# Example: identify AMD driver versions on Windows via PowerShell
Get-WmiObject Win32_PnPSignedDriver | Where-Object { $_.DeviceName -match 'AMD' } | Select-Object DeviceName, DriverVersion