CVE-2020-8695
Description
A vulnerability was found in Intel's implementation of RAPL (Running Average Power Limit). An attacker with a local account could query the power management functionality to intelligently infer SGX enclave computation values by measuring power usage in the RAPL subsystem.
Security Bulletin
Mitigation
Until a firmware update and reboot can be applied, the attack vector can be reduced by limiting read access to the sysfs attributes that export this functionality to userspace.
The command:
sudo chmod 400 /sys/class/powercap/intel_rapl/*/energy_ujWill do this for the current boot, it will need to be scripted to run at each boot to remain persistent across reboots.
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 | 5.1 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/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
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Acknowledgements
Red Hat would like to thank Intel for reporting this issue.
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