CVE-2025-29951: AMD Secure Processor Buffer Overflow Flaw

CVE-2025-29951 Overview

A buffer overflow vulnerability exists in the AMD Secure Processor (ASP) bootloader that could allow an attacker with local access and low privileges to overwrite memory. This stack-based buffer overflow (CWE-121) may lead to privilege escalation and arbitrary code execution, potentially compromising the security foundation of AMD-based systems.

Critical Impact

Successful exploitation could allow attackers to execute arbitrary code at the ASP level, bypassing hardware security mechanisms and gaining control over the system's secure processing environment.

Affected Products

• AMD Secure Processor (ASP) Bootloader
• AMD-based systems utilizing the affected ASP firmware

Discovery Timeline

• 2026-02-10 - CVE CVE-2025-29951 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2025-29951

Vulnerability Analysis

This vulnerability affects the AMD Secure Processor (ASP), a dedicated security subsystem embedded within AMD processors that handles critical security functions including secure boot, trusted execution environments, and cryptographic operations. The ASP bootloader contains a stack-based buffer overflow vulnerability that occurs when processing input data without proper boundary validation.

The attack requires local access to the system with low-level privileges, though the complexity of exploitation is high due to the specialized nature of the ASP environment. Successful exploitation allows an attacker to overwrite adjacent memory regions on the stack, potentially corrupting return addresses or function pointers. This can redirect program execution flow to attacker-controlled code, resulting in arbitrary code execution within the secure processor context.

The impact is significant because the ASP operates at a privilege level below the operating system, meaning code execution at this level could potentially bypass traditional security controls including secure boot protections.

Root Cause

The vulnerability stems from a stack-based buffer overflow condition (CWE-121) in the ASP bootloader code. This occurs when the bootloader fails to properly validate the size of input data before copying it into a fixed-size stack buffer. Without adequate bounds checking, oversized input can overflow the allocated buffer space, overwriting adjacent stack memory including return addresses and saved registers.

Attack Vector

The attack vector requires local access to the target system. An attacker with low privileges must craft malicious input designed to trigger the buffer overflow condition in the ASP bootloader. The high attack complexity indicates that successful exploitation requires specific conditions or sophisticated techniques:

1. The attacker must have local access to a system with a vulnerable AMD processor
2. A method to deliver malicious input to the ASP bootloader must be available
3. The attacker must craft a payload that precisely overwrites memory to achieve code execution
4. Memory layout and protection mechanisms may need to be bypassed

Due to the sensitive nature of firmware-level vulnerabilities and the absence of verified proof-of-concept code, specific exploitation details are not provided. Refer to the AMD Security Bulletin SB-4013 for additional technical information.

Detection Methods for CVE-2025-29951

Indicators of Compromise

• Unexpected modifications to ASP firmware or bootloader components
• Anomalous system behavior during boot sequences or secure processor operations
• Evidence of unauthorized local access attempts targeting low-level firmware interfaces
• Unusual error logs related to the AMD Secure Processor subsystem

Detection Strategies

• Implement firmware integrity monitoring to detect unauthorized changes to ASP bootloader components
• Deploy endpoint detection solutions capable of monitoring firmware-level activity
• Review system logs for signs of exploitation attempts targeting AMD processor security features
• Utilize hardware security attestation mechanisms to verify bootloader integrity

Monitoring Recommendations

• Enable AMD Platform Security Processor (PSP) logging where available
• Monitor for unusual patterns in secure boot attestation processes
• Implement continuous firmware integrity verification solutions
• Deploy SentinelOne Singularity platform for comprehensive endpoint protection and firmware-level threat detection

How to Mitigate CVE-2025-29951

Immediate Actions Required

• Review the AMD Security Bulletin SB-4013 for affected product versions and remediation guidance
• Inventory all systems with AMD processors that may be affected by this vulnerability
• Restrict local access to affected systems to trusted users only
• Apply firmware updates as soon as they become available from AMD or system OEMs
• Implement defense-in-depth strategies to limit the impact of potential exploitation

Patch Information

AMD has released a security bulletin addressing this vulnerability. System administrators should consult the AMD Security Bulletin SB-4013 for specific patch information and affected product details. Firmware updates are typically distributed through OEM partners and system BIOS updates, so organizations should also check with their hardware vendors for applicable updates.

Workarounds

• Limit local system access to essential personnel only until patches can be applied
• Enable additional access controls and monitoring on affected systems
• Implement network segmentation to isolate potentially vulnerable systems
• Review and enforce strict physical access controls for affected hardware

Organizations should prioritize applying official firmware updates when available, as workarounds provide only partial protection against this vulnerability class.