CVE-2025-27572 Overview
CVE-2025-27572 is a transient execution vulnerability affecting Intel Trust Domain Extensions (TDX) within Ring 0 hypervisor components. This side-channel attack enables information disclosure through speculative execution pathways, potentially allowing a privileged attacker with local access to expose sensitive data from protected memory regions.
Critical Impact
Privileged attackers with local access to hypervisor-level components may exploit transient execution behavior to leak confidential information from Intel TDX environments, compromising the confidentiality guarantees of trusted execution domains.
Affected Products
- Intel processors with Trust Domain Extensions (TDX) capability
- Hypervisor software utilizing Intel TDX features
- Virtualization platforms leveraging TDX for confidential computing
Discovery Timeline
- 2026-02-10 - CVE CVE-2025-27572 published to NVD
- 2026-02-10 - Last updated in NVD database
Technical Details for CVE-2025-27572
Vulnerability Analysis
This vulnerability exploits transient execution behavior in Intel's Trust Domain Extensions (TDX) technology operating at Ring 0 (hypervisor privilege level). TDX is designed to create hardware-isolated Trust Domains (TDs) that provide strong confidentiality and integrity protections for virtual machines. However, this flaw allows certain speculative execution side channels to leak information during transient operations.
The attack requires high complexity and must be performed by an authorized adversary with privileged access to the hypervisor layer. While the attack does not require user interaction or special internal knowledge once initial access is obtained, the technical barriers to exploitation remain significant due to the local access requirement and the need for elevated privileges within the hypervisor context.
The vulnerability impacts only confidentiality—there are no integrity or availability implications. The scope is limited to the vulnerable system itself, with no chained impacts on subsequent systems.
Root Cause
The root cause lies in the transient execution behavior of Intel TDX implementations at the hypervisor level. During speculative execution, the processor may transiently access sensitive memory contents before architectural security checks are completed. Although these speculative operations are eventually rolled back, the data accessed during this window can be extracted through various side-channel techniques such as cache timing analysis.
This represents a fundamental challenge in reconciling speculative execution optimizations with the confidentiality guarantees that TDX is designed to provide. The transient window creates a covert channel that bypasses the isolation boundaries normally enforced by the TDX architecture.
Attack Vector
The attack requires local access to a system with Intel TDX capabilities and hypervisor-level (Ring 0) privileges. An authorized adversary who has already achieved privileged access within the hypervisor context can craft specific instruction sequences that trigger transient execution paths accessing protected memory regions.
The attacker leverages timing-based side channels to observe the microarchitectural state changes caused by speculative memory accesses. By carefully measuring cache timing or other observable effects, the attacker can reconstruct sensitive data that should have remained protected within Trust Domains.
The vulnerability does not require user interaction or specialized knowledge of the target system's internal state, making it exploitable once the prerequisite privileged access is obtained.
Detection Methods for CVE-2025-27572
Indicators of Compromise
- Unusual cache access patterns or timing anomalies in hypervisor-level monitoring
- Unexpected privileged operations targeting TDX memory regions
- Anomalous performance counter readings indicating speculative execution abuse
Detection Strategies
- Deploy hardware performance counter monitoring to detect suspicious speculative execution patterns at the hypervisor level
- Implement memory access auditing for TDX-protected regions to identify unauthorized access attempts
- Monitor for unusual timing variations in cache operations that may indicate side-channel exploitation
Monitoring Recommendations
- Enable Intel Processor Trace (PT) capabilities to capture detailed execution traces for forensic analysis
- Configure hypervisor-level security monitoring to alert on anomalous Ring 0 operations
- Establish baseline performance metrics to identify deviations indicative of side-channel attacks
How to Mitigate CVE-2025-27572
Immediate Actions Required
- Review and apply the latest Intel microcode updates addressing this vulnerability
- Restrict hypervisor-level access to only essential trusted administrators
- Evaluate the deployment of additional isolation mechanisms for TDX workloads
Patch Information
Intel has released a security advisory addressing this vulnerability. System administrators should consult the Intel Security Advisory SA-01397 for detailed patch information, updated microcode, and remediation guidance specific to their hardware and software configurations.
Contact your hypervisor vendor (VMware, Microsoft Hyper-V, KVM, etc.) to obtain updated virtualization software that incorporates the necessary mitigations for this transient execution vulnerability.
Workarounds
- Limit administrative access to hypervisor components to reduce the attack surface for privileged adversaries
- Consider disabling TDX features on systems where confidential computing requirements can be met through alternative isolation mechanisms
- Implement strict network segmentation to limit local access pathways to TDX-enabled systems
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
