SB2020092607 - Information disclosure in Linux kernel



SB2020092607 - Information disclosure in Linux kernel

Published: September 26, 2020

Security Bulletin ID SB2020092607
Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Race condition (CVE-ID: CVE-2020-10766)

The vulnerability allows a local user to gain access to sensitive information.

A logic bug flaw was found in Linux kernel before 5.8-rc1 in the implementation of SSBD. A bug in the logic handling allows an attacker with a local account to disable SSBD protection during a context switch when additional speculative execution mitigations are in place. This issue was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching.


2) Resource management error (CVE-ID: CVE-2020-10767)

The vulnerability allows a local user to gain access to sensitive information.

A flaw was found in the Linux kernel before 5.8-rc1 in the implementation of the Enhanced IBPB (Indirect Branch Prediction Barrier). The IBPB mitigation will be disabled when STIBP is not available or when the Enhanced Indirect Branch Restricted Speculation (IBRS) is available. This flaw allows a local user to perform a Spectre V2 style attack when this configuration is active.


Remediation

Install update from vendor's website.