SB2021032231 - Fedora 33 update for kernel



SB2021032231 - Fedora 33 update for kernel

Published: March 22, 2021

Security Bulletin ID SB2021032231
Severity
Low
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) 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.


2) 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.


3) Excessive Iteration (CVE-ID: CVE-2021-28950)

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to excessive iteration in fs/fuse/fuse_i.h in the Linux kernel. A local user can run a specially crafted program to perform a denial of service attack.


Remediation

Install update from vendor's website.