SB2021032231 - Fedora 33 update for kernel
Published: March 22, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Off-by-one (CVE-ID: CVE-2020-27171)
CWE-ID: CWE-193 - Off-by-one Error
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
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)
CWE-ID: CWE-203 - Observable discrepancy
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
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)
CWE-ID: CWE-834 - Excessive Iteration
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
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.