CVE-2020-12965 in AMD
Summary
by MITRE • 02/05/2022
When combined with specific software sequences, AMD CPUs may transiently execute non-canonical loads and store using only the lower 48 address bits potentially resulting in data leakage.
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Analysis
by VulDB Data Team • 06/30/2026
This vulnerability represents a sophisticated transient execution flaw affecting AMD processors that operates through the manipulation of address space handling during memory operations. The issue manifests when specific software sequences trigger AMD CPUs to perform non-canonical loads and stores while utilizing only the lower 48 bits of address space, creating potential pathways for sensitive data exposure. This behavior aligns with CWE-1276 which addresses improper handling of address space in processor architectures, specifically targeting transient execution vulnerabilities that leverage microarchitectural features.
The technical implementation involves AMD processors' handling of memory addresses where certain instruction sequences cause the CPU to temporarily operate with truncated address information, effectively creating a window where data can be accessed through non-canonical memory locations. This vulnerability exploits the processor's speculative execution mechanisms, allowing malicious code to potentially observe or manipulate data that should remain isolated within protected memory regions. The flaw demonstrates characteristics consistent with the ATT&CK framework's T1059.001 technique for command and scripting interpreter usage, as it requires specific software sequences to trigger the vulnerable behavior.
The operational impact extends beyond simple information disclosure, as this vulnerability can potentially enable attackers to extract cryptographic keys, passwords, or other sensitive data from memory regions that should remain protected. The transient nature of the execution means that traditional mitigation approaches like recompilation or microcode updates may not fully address all attack vectors, requiring comprehensive system-level security measures. This vulnerability affects systems where AMD processors are utilized in environments handling sensitive data, particularly impacting cloud computing platforms and enterprise servers where multiple tenants share hardware resources.
Mitigation strategies must address both software and hardware components through coordinated approaches including microcode updates from AMD, operating system patches that implement kernel page table isolation, and application-level protections such as control flow integrity checks. Organizations should implement comprehensive monitoring for unusual memory access patterns and consider architectural mitigations like disabling speculative execution where possible. The vulnerability highlights the importance of understanding processor microarchitecture in security design and demonstrates how seemingly benign address space handling can create significant security risks when combined with specific software execution flows.