CVE-2018-3620 in Intel
Summary
by MITRE
Systems with microprocessors utilizing speculative execution and address translations may allow unauthorized disclosure of information residing in the L1 data cache to an attacker with local user access via a terminal page fault and a side-channel analysis.
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Analysis
by VulDB Data Team • 05/30/2026
This vulnerability represents a sophisticated side-channel attack exploiting the fundamental mechanisms of modern processor architectures that utilize speculative execution and memory management. The flaw resides in how microprocessors handle address translations during speculative execution phases, creating a pathway for information leakage through the L1 data cache. Systems affected include processors implementing Intel's speculative execution mechanisms and similar architectures that employ similar caching and translation techniques. The vulnerability specifically leverages the interaction between memory management units and cache subsystems during page fault handling procedures, where the processor's speculative behavior can inadvertently expose cached data to unauthorized access.
The technical implementation of this vulnerability involves exploiting the timing differences and cache state variations that occur during page fault processing in speculative execution environments. When a page fault occurs, the processor's memory management unit performs address translation while the speculative execution engine continues processing instructions. This creates a window where cached data from previous operations can be accessed through timing analysis and cache state monitoring. The attack requires local user access and leverages the fact that the processor's cache management during speculative execution does not properly isolate data from different memory contexts, allowing an attacker to infer information from the cache state through carefully crafted side-channel analysis techniques. This aligns with CWE-200, which addresses information exposure through side channels, and represents a classic example of a cache timing attack vector.
The operational impact of CVE-2018-3620 extends beyond simple information disclosure, as it can potentially expose sensitive data including cryptographic keys, passwords, and other confidential information stored in the processor's L1 cache. Attackers can leverage this vulnerability to perform cache-based information leakage attacks that are particularly dangerous in multi-tenant environments or systems where different processes share the same physical processor core. The vulnerability affects systems where speculative execution is enabled, which includes most modern processors manufactured by major vendors including Intel, AMD, and ARM. This affects a broad range of computing environments from desktop systems to server infrastructure, making it particularly concerning for enterprise security. The attack can be executed with minimal privileges and does not require specialized hardware, making it accessible to a wide range of threat actors and potentially enabling sophisticated persistent attacks.
Mitigation strategies for this vulnerability typically involve implementing software-level protections such as kernel patches that modify how page faults are handled and how memory is managed during speculative execution. These patches often introduce additional memory barriers and cache management controls to prevent the leakage of information through cache state changes. System administrators should also consider disabling speculative execution features where possible, though this may impact performance. Hardware-level mitigations include processor microcode updates that modify the cache management behavior during page fault handling and address translation. Organizations should implement comprehensive monitoring solutions to detect anomalous cache behavior and timing variations that might indicate exploitation attempts. The mitigation approach aligns with ATT&CK technique T1059 which covers command and control through system and network discovery, and represents a classic example of how modern processor security vulnerabilities require both software and hardware remediation approaches to address effectively.