Weakness · Medium
CWE-1303: Non-Transparent Sharing of Microarchitectural Resources
What it is
Hardware structures shared across execution contexts (e.g., caches and branch predictors) can violate the expected architecture isolation between contexts.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
Modern processors use techniques such as out-of-order execution, speculation, prefetching, data forwarding, and caching to increase performance. Details about the implementation of these techniques are hidden from the programmer's view. This is problematic when the hardware implementation of these techniques results in resources being shared across supposedly isolated contexts. Contention for shared resources between different contexts opens covert channels that allow malicious programs executing in one context to recover information from another context. Some examples of shared micro-architectural resources that have been used to leak information between contexts are caches, branch prediction logic, and load or store buffers. Speculative and out-of-order execution provides an attacker with increased control over which data is leaked through the covert channel. If the extent of resource sharing between contexts in the design microarchitecture is undocumented, it is extremely difficult to ensure system assets are protected against disclosure.
What an attacker can do
- Read Application Data (Confidentiality)
- Read Memory (Confidentiality)
How to prevent it
Architecture and Design
- Microarchitectural covert channels can be addressed using a mixture of hardware and software mitigation techniques. These include partitioned caches, new barrier and flush instructions, and disabling high resolution performance counters and timers.
Requirements
- Microarchitectural covert channels can be addressed using a mixture of hardware and software mitigation techniques. These include partitioned caches, new barrier and flush instructions, and disabling high resolution performance counters and timers.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.