CVE-2018-9056
Description
BranchScope is a new class of attack which leverages functioning of the Branch Prediction Unit (BPU) of a processor to infer/leak sensitive process information, which is involved in the branch decision making (if (x) { x ^ y; } else {x & y;}). In this, BranchScope side-channel could help to infer 'x', by observing prediction patterns of the Branch Prediction Unit (BPU).
Mitigation
This is a hardware processor issue, not a Linux kernel flaw. The flaw specifically targets software which uses sensitive information in branching expressions. A software mitigation could be for the target software to avoid the use of sensitive data bits in (if..else) branching decisions or to avoid (if..else) branching altogether.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.6 | 5.6 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Frequently Asked Questions
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