SB2021032922 - Spectre mitigations bypass in Linux kernel

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Main Vulnerability Database SB2021032922

SB2021032922 - Spectre mitigations bypass in Linux kernel

Published: March 29, 2021

Security Bulletin ID SB2021032922
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) Observable discrepancy (CVE-ID: CVE-2020-27170)

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

The vulnerability exists in kernel/bpf/verifier.c due to kernel performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations. A local user can run a specially crafted program to gain access to sensitive information.


2) Off-by-one (CVE-ID: CVE-2020-27171)

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

The vulnerability exists due to an off-by-one error in kernel/bpf/verifier.c affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations. A local user can run a specially crafted program to gain access to sensitive information on the system.


Remediation

Install update from vendor's website.

References