CVE-2020-27171: Medium severity Linux Linux kernel vulnerability

Published Mar 18, 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.

Other sources

In retrieveptrlimit of verifier.c, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.

— OSV

Affected Software

90 affected componentsFixes available
Linux Linux kernel<5.11.8
Fedoraproject Fedora=32
Fedoraproject Fedora=33
Fedoraproject Fedora=34
Debian Debian Linux=9.0
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=20.04
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.22-16.12.25-1
android/:linux_kernel:>=:0<:2021-07-05
:2021-07-05
ubuntu/linux-azure<4.15.0-1111.123~14.04.1
4.15.0-1111.123~14.04.1
ubuntu/linux-aws*
ubuntu/linux-lts-xenial*
ubuntu/linux-aws-hwe<4.15.0-1097.104~16.04.1
4.15.0-1097.104~16.04.1
ubuntu/linux-azure<4.15.0-1111.123~16.04.1
4.15.0-1111.123~16.04.1
ubuntu/linux-gcp<4.15.0-1096.109~16.04.1
4.15.0-1096.109~16.04.1
ubuntu/linux-hwe<4.15.0-140.144~16.04.1
4.15.0-140.144~16.04.1
ubuntu/linux-oracle<4.15.0-1068.76~16.04.1
4.15.0-1068.76~16.04.1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-hwe-edge*
ubuntu/linux-kvm*
ubuntu/linux-fips*
ubuntu/linux-fips*
ubuntu/linux<4.15.0-140.144
4.15.0-140.144
ubuntu/linux-aws<4.15.0-1097.104
4.15.0-1097.104
ubuntu/linux-aws-5.4<5.4.0-1041.43~18.04.1
5.4.0-1041.43~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1111.123
4.15.0-1111.123
ubuntu/linux-azure-5.4<5.4.0-1043.45~18.04.1
5.4.0-1043.45~18.04.1
ubuntu/linux-dell300x<4.15.0-1015.19
4.15.0-1015.19
ubuntu/linux-gcp-4.15<4.15.0-1096.109
4.15.0-1096.109
ubuntu/linux-gcp-5.4<5.4.0-1040.43~18.04.1
5.4.0-1040.43~18.04.1
ubuntu/linux-gke-5.3<5.3.0-1041.44
5.3.0-1041.44
ubuntu/linux-gke-5.4<5.4.0-1039.41~18.04.1
5.4.0-1039.41~18.04.1
ubuntu/linux-gkeop-5.4<5.4.0-1012.13~18.04.1
5.4.0-1012.13~18.04.1
ubuntu/linux-hwe<5.3.0-72.68
5.3.0-72.68
ubuntu/linux-hwe-5.4<5.4.0-70.78~18.04.1
5.4.0-70.78~18.04.1
ubuntu/linux-kvm<4.15.0-1088.90
4.15.0-1088.90
ubuntu/linux-oracle<4.15.0-1068.76
4.15.0-1068.76
ubuntu/linux-oracle-5.4<5.4.0-1041.44~18.04.1
5.4.0-1041.44~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1032.35~18.04.1
5.4.0-1032.35~18.04.1
ubuntu/linux-raspi2<4.15.0-1082.87
4.15.0-1082.87
ubuntu/linux-raspi2-5.3<5.3.0-1038.40
5.3.0-1038.40
ubuntu/linux-snapdragon<4.15.0-1099.108
4.15.0-1099.108
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-edge*
ubuntu/linux-gke-4.15*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-fips<4.15.0-2040.42
4.15.0-2040.42
ubuntu/linux-azure-fips<4.15.0-2023.26
4.15.0-2023.26
ubuntu/linux-fips<4.15.0-1056.64
4.15.0-1056.64
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.4.0-70.78
5.4.0-70.78
ubuntu/linux-aws<5.4.0-1041.43
5.4.0-1041.43
ubuntu/linux-azure<5.4.0-1043.45
5.4.0-1043.45
ubuntu/linux-gcp<5.4.0-1040.43
5.4.0-1040.43
ubuntu/linux-gke<5.4.0-1039.41
5.4.0-1039.41
ubuntu/linux-gkeop<5.4.0-1012.13
5.4.0-1012.13
ubuntu/linux-hwe-5.8<5.8.0-48.54~20.04.1
5.8.0-48.54~20.04.1
ubuntu/linux-kvm<5.4.0-1036.37
5.4.0-1036.37
ubuntu/linux-oem-5.10<5.10.0-1019.20
5.10.0-1019.20
ubuntu/linux-oem-5.6<5.6.0-1052.56
5.6.0-1052.56
ubuntu/linux-oracle<5.4.0-1041.44
5.4.0-1041.44
ubuntu/linux-raspi<5.4.0-1032.35
5.4.0-1032.35
ubuntu/linux-riscv-5.8<5.8.0-20.22~20.04.1
5.8.0-20.22~20.04.1
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-aws-fips<5.4.0-1069.73+fips2
5.4.0-1069.73+fips2
ubuntu/linux-azure-fips<5.4.0-1073.76+fips1
5.4.0-1073.76+fips1
ubuntu/linux-gcp-fips<5.4.0-1067.71~20.04.1
5.4.0-1067.71~20.04.1
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-realtime*
ubuntu/linux-raspi-realtime*
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.22-1Fixed in 6.12.25-1
  2. Upgrade

    Upgrade android/:linux_kernel: to a version that resolves this vulnerability.

    Fixed in :2021-07-05
  3. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1111.123~14.04.1
  4. Upgrade

    Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-1097.104~16.04.1
  5. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1111.123~16.04.1
  6. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 4.15.0-1096.109~16.04.1
  7. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-140.144~16.04.1
  8. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1068.76~16.04.1
  9. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 4.15.0-140.144
  10. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.15.0-1097.104
  11. Upgrade

    Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1041.43~18.04.1
  12. Upgrade

    Upgrade ubuntu/linux-azure-4.15 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1111.123
  13. Upgrade

    Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1043.45~18.04.1
  14. Upgrade

    Upgrade ubuntu/linux-dell300x to a version that resolves this vulnerability.

    Fixed in 4.15.0-1015.19
  15. Upgrade

    Upgrade ubuntu/linux-gcp-4.15 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1096.109
  16. Upgrade

    Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1040.43~18.04.1
  17. Upgrade

    Upgrade ubuntu/linux-gke-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1041.44
  18. Upgrade

    Upgrade ubuntu/linux-gke-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1039.41~18.04.1
  19. Upgrade

    Upgrade ubuntu/linux-gkeop-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1012.13~18.04.1
  20. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 5.3.0-72.68
  21. Upgrade

    Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-70.78~18.04.1
  22. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 4.15.0-1088.90
  23. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1068.76
  24. Upgrade

    Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1041.44~18.04.1
  25. Upgrade

    Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1032.35~18.04.1
  26. Upgrade

    Upgrade ubuntu/linux-raspi2 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1082.87
  27. Upgrade

    Upgrade ubuntu/linux-raspi2-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1038.40
  28. Upgrade

    Upgrade ubuntu/linux-snapdragon to a version that resolves this vulnerability.

    Fixed in 4.15.0-1099.108
  29. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2040.42
  30. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2023.26
  31. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-1056.64
  32. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.4.0-70.78
  33. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.4.0-1041.43
  34. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.4.0-1043.45
  35. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.4.0-1040.43
  36. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 5.4.0-1039.41
  37. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.4.0-1012.13
  38. Upgrade

    Upgrade ubuntu/linux-hwe-5.8 to a version that resolves this vulnerability.

    Fixed in 5.8.0-48.54~20.04.1
  39. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.4.0-1036.37
  40. Upgrade

    Upgrade ubuntu/linux-oem-5.10 to a version that resolves this vulnerability.

    Fixed in 5.10.0-1019.20
  41. Upgrade

    Upgrade ubuntu/linux-oem-5.6 to a version that resolves this vulnerability.

    Fixed in 5.6.0-1052.56
  42. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.4.0-1041.44
  43. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 5.4.0-1032.35
  44. Upgrade

    Upgrade ubuntu/linux-riscv-5.8 to a version that resolves this vulnerability.

    Fixed in 5.8.0-20.22~20.04.1
  45. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1069.73+fips2
  46. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1073.76+fips1
  47. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1067.71~20.04.1
  48. Upgrade

    Upgrade Linux kernel to a version that resolves this vulnerability.

    Fixed in 5.11.8

Event History

Mar 18, 2021
CVE Published
via OSV·10:00 PM
Data Sourced
via OSV·10:00 PM
DescriptionSeverityAffected Software
Mar 20, 2021
CVE Published
via MITRE·09:41 PM
Data Sourced
via MITRE·09:41 PM
Description
Data Sourced
via NVD·10:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Jul 1, 2021
Advisory Published
via OSV·12:00 AM

Frequently Asked Questions

1

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.

2

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.

3

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.

4

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.

5

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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