medium
6
CWE
193
Advisory Published
Updated

CVE-2020-27171

First published: Sat Mar 20 2021(Updated: )

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
Linux Kernel<5.11.8
Fedoraproject Fedora=32
Fedoraproject Fedora=33
Fedoraproject Fedora=34
Debian GNU/Linux=9.0
Ubuntu Linux=14.04
Ubuntu Linux=16.04
Ubuntu Linux=18.04
Ubuntu Linux=20.04
debian/linux
5.10.223-1
5.10.226-1
6.1.123-1
6.1.128-1
6.12.12-1
6.12.13-1
Fedora=32
Fedora=33
Fedora=34
Debian=9.0
Ubuntu=14.04
Ubuntu=16.04
Ubuntu=18.04
Ubuntu=20.04

Remedy

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8

Remedy

https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/patch/?id=10d2bb2e6b1d8c4576c56a748f697dbeb8388899

Remedy

https://www.openwall.com/lists/oss-security/2021/03/19/3

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2020-27171?

    CVE-2020-27171 is considered critical due to its potential to enable side-channel attacks that can bypass mitigations for Spectre vulnerabilities.

  • How do I fix CVE-2020-27171?

    To fix CVE-2020-27171, update the Linux kernel to version 5.11.8 or later, or apply available patches for affected distributions.

  • Which Linux distributions are affected by CVE-2020-27171?

    CVE-2020-27171 affects multiple distributions including Fedora, Debian, and Ubuntu versions prior to their respective security updates.

  • What kind of vulnerability is CVE-2020-27171?

    CVE-2020-27171 is an off-by-one error in the Linux kernel's BPF verifier that can lead to integer underflow and side-channel attacks.

  • What is the potential impact of CVE-2020-27171?

    The potential impact of CVE-2020-27171 includes unauthorized access to sensitive information through process memory exposure.

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