CVE-2018-3639
Description
An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions (a commonly used performance optimization). It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to read privileged memory by conducting targeted cache side-channel attacks.
Statement
Red Hat Product Security is aware of this issue. Updates will be released as they become available. For additional information, please refer to the Red Hat Knowledgebase article: https://access.redhat.com/security/vulnerabilities/ssbd
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.6 | 5.5 | 5.5 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Changed | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | None | None | None |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Other
Technical Impact: Read Application Data; Other
Information exposure.
Acknowledgements
Red Hat would like to thank Jann Horn (Google Project Zero) and Ken Johnson (Microsoft Security Response Center) for reporting this issue.
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