CVE-2018-3640
Description
An industry-wide issue was found in the way many modern microprocessor handle speculative access of system registers inaccessible to unprivileged user. It relies on the presence of a precisely-defined instruction sequence in the privileged code which allows speculative load of system registers and that such register value could be subsequently used in speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to read privileged system registers by conducting targeted cache side-channel attacks.
Statement
This is a hardware issue and is not currently planned to be mitigated in software (in the Linux kernel). As such, we do not plan to provide mitigations for this issue in the kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7, and Red Hat Enterprise MRG 2.
Future CPU vendor microcode updates may address this issue.
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 | 2.8 | 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 | Low | 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:L/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
Covert storage channels may provide attackers with important information about the system in question.
Integrity,Confidentiality
Technical Impact: Read Application Data
If these messages or packets are sent with unnecessary data contained within, it may tip off malicious listeners as to the process that created the message. With this information, attackers may learn any number of things, including the hardware platform, operating system, or algorithms used by the sender. This information can be of significant value to the user in launching further attacks.
Frequently Asked Questions
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