CVE-2025-29950 in EPYC 9004 Processors
Summary
by MITRE • 02/10/2026
Improper input validation in system management mode (SMM) could allow a privileged attacker to overwrite stack memory leading to arbitrary code execution.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/11/2026
The vulnerability identified as CVE-2025-29950 resides within the system management mode of modern computing platforms, representing a critical weakness in the foundational firmware architecture that governs low-level system operations. System management mode operates as a privileged execution environment that handles critical system functions including power management, hardware configuration, and system monitoring. This mode operates with elevated privileges and direct access to system hardware, making it a prime target for attackers seeking to establish persistent control over computing platforms. The vulnerability specifically manifests in the input validation mechanisms that govern how data flows into the SMM execution context, creating a potential pathway for malicious actors to manipulate system behavior through carefully crafted inputs that bypass normal security checks.
The technical flaw stems from inadequate validation of input parameters within the SMM handler routines, allowing an attacker with existing privileged access to manipulate memory structures through stack overwrites. This improper validation creates a condition where malicious inputs can cause buffer overflows or memory corruption within the SMM execution environment, potentially enabling an attacker to overwrite critical stack memory locations. The vulnerability's exploitation requires an attacker to already possess elevated privileges within the system, typically achieved through prior compromise of operating system level components or other attack vectors that allow code execution with sufficient privileges to trigger the vulnerable SMM code path. The stack memory overwrite can potentially redirect execution flow to attacker-controlled code, creating a persistent backdoor that operates below the operating system level and remains undetected by conventional security tools.
The operational impact of this vulnerability extends far beyond typical software security flaws, as it fundamentally compromises the integrity of the system's core firmware infrastructure. Attackers exploiting this vulnerability can achieve arbitrary code execution within the SMM context, which operates with the highest privilege level and direct hardware access capabilities. This enables sophisticated attack scenarios including persistent rootkit installation, hardware-level surveillance, and complete system compromise that bypasses traditional operating system security controls. The vulnerability's nature makes it particularly dangerous because SMM operates outside the normal operating system execution environment and is not subject to typical memory protection mechanisms. Additionally, the compromised system state can persist across reboots, making detection and remediation extremely challenging. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a significant concern for the ATT&CK framework's privilege escalation and persistence techniques.
Mitigation strategies for CVE-2025-29950 must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities in future firmware implementations. The most effective immediate response involves firmware updates from vendors that patch the input validation flaws within SMM handlers, though these updates may require specific procedures and could potentially impact system stability. Organizations should implement comprehensive firmware integrity monitoring solutions that can detect unauthorized modifications to SMM components, as these protections operate at a level below traditional endpoint detection and response systems. System administrators should also consider implementing secure boot configurations that validate firmware integrity at system startup, combined with memory protection features like kernel address space layout randomization and stack canaries that can help detect exploitation attempts. The vulnerability highlights the importance of applying the principle of least privilege even within firmware environments and demonstrates the critical need for regular security assessments of low-level system components, aligning with industry best practices for embedded system security and firmware hardening standards.