CVE-2025-29934 in EPYC 9004 Processors
Summary
by MITRE • 11/21/2025
A bug within some AMD CPUs could allow a local admin-privileged attacker to run a SEV-SNP guest using stale TLB entries, potentially resulting in loss of data integrity.
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Analysis
by VulDB Data Team • 11/25/2025
The vulnerability identified as CVE-2025-29934 resides within AMD Central Processing Units and represents a significant security flaw that exploits the interaction between the Secure Encrypted Virtualization - Secure Nested Paging (SEV-SNP) feature and Translation Lookaside Buffer (TLB) management mechanisms. This issue specifically affects systems where AMD CPUs implement SEV-SNP functionality, creating a potential pathway for privilege escalation attacks that could compromise data integrity within virtualized environments.
The technical flaw manifests when a local attacker with administrative privileges executes malicious code that leverages stale TLB entries to manipulate the memory management of SEV-SNP guests. This vulnerability stems from improper handling of memory mappings during virtual machine transitions, where the CPU fails to properly invalidate or refresh TLB entries that should be cleared when switching between different memory contexts. The flaw operates at the hardware level within the CPU's memory management unit, making it particularly challenging to detect and mitigate through traditional software-based approaches.
The operational impact of this vulnerability extends beyond simple data integrity concerns, potentially enabling attackers to access sensitive information within SEV-SNP protected virtual machines. When an attacker successfully exploits this weakness, they can potentially read or modify data that should remain isolated within the secure virtual environment, undermining the fundamental security guarantees that SEV-SNP is designed to provide. The attack vector requires local administrative access, but this privilege level is often sufficient to establish persistent access within compromised systems, especially in enterprise environments where administrative accounts are frequently used.
Mitigation strategies for CVE-2025-29934 should focus on both hardware and software remediations, with AMD releasing microcode updates that address the specific TLB handling issue. Organizations should prioritize applying these updates immediately, particularly in environments running SEV-SNP enabled virtual machines. Additionally, implementing strict access controls and monitoring for administrative account usage can help detect potential exploitation attempts. The vulnerability aligns with CWE-119 which addresses memory access violations, and represents a specific instance of how hardware-level security features can be undermined by improper memory management. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as attackers leverage administrative privileges to exploit the underlying hardware flaw.
The broader implications of this vulnerability highlight the increasing complexity of modern CPU security features and the challenges of maintaining secure memory management in virtualized environments. As virtualization technologies become more sophisticated, the attack surface expands, requiring security teams to understand not just software vulnerabilities but also the intricate hardware behaviors that can be exploited. This particular flaw demonstrates how seemingly minor memory management issues can have significant security consequences, particularly when combined with advanced security features like SEV-SNP that are designed to protect against sophisticated attacks. Organizations should conduct thorough assessments of their virtualized environments and ensure that all systems running SEV-SNP functionality are updated with the latest microcode patches to prevent potential exploitation of this vulnerability.