CVE-2020-25212: High severity Linux Linux kernel vulnerability

Published Sep 9, 2020
·
Updated

A flaw was found in the NFSv4 implementation where when mounting a remote attacker controlled server it could return specially crafted response allow for local memory corruption and possibly privilege escalation.

Other sources

A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.

— Ubuntu

A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c.

References:

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.3 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4487b93545214a9db8cbf32e86411677b0cca21 https://twitter.com/grsecurity/status/1303370421958578179

— Red Hat

Affected Software

88 affected componentsFixes available
redhat/kernel-rt<0:3.10.0-1160.11.1.rt56.1145.el7
0:3.10.0-1160.11.1.rt56.1145.el7
redhat/kernel-alt<0:4.14.0-115.32.1.el7a
0:4.14.0-115.32.1.el7a
redhat/kernel<0:3.10.0-1160.11.1.el7
0:3.10.0-1160.11.1.el7
redhat/kernel<0:3.10.0-693.82.1.el7
0:3.10.0-693.82.1.el7
redhat/kernel<0:3.10.0-957.70.1.el7
0:3.10.0-957.70.1.el7
redhat/kernel<0:3.10.0-1062.45.1.el7
0:3.10.0-1062.45.1.el7
redhat/kernel-rt<0:4.18.0-305.rt7.72.el8
0:4.18.0-305.rt7.72.el8
redhat/kernel<0:4.18.0-305.el8
0:4.18.0-305.el8
Linux Linux kernel<5.8.3
Debian Debian Linux=9.0
openSUSE Leap=15.1
openSUSE Leap=15.2
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=20.04
debian/linux
6.1.176-16.1.190-16.12.107-16.12.113-17.2.12-17.2.13-1
ubuntu/linux-aws<4.4.0-1078.82
4.4.0-1078.82
ubuntu/linux-azure<4.15.0-1098.109~14.04.1
4.15.0-1098.109~14.04.1
ubuntu/linux-lts-xenial<4.4.0-190.220~14.04.1
4.4.0-190.220~14.04.1
ubuntu/linux*
ubuntu/linux<4.4.0-190.220
4.4.0-190.220
ubuntu/linux-aws<4.4.0-1114.127
4.4.0-1114.127
ubuntu/linux-aws-hwe<4.15.0-1085.90~16.04.1
4.15.0-1085.90~16.04.1
ubuntu/linux-azure<4.15.0-1098.109~16.04.1
4.15.0-1098.109~16.04.1
ubuntu/linux-gcp<4.15.0-1086.98~16.04.1
4.15.0-1086.98~16.04.1
ubuntu/linux-hwe<4.15.0-120.122~16.04.1
4.15.0-120.122~16.04.1
ubuntu/linux-kvm<4.4.0-1080.87
4.4.0-1080.87
ubuntu/linux-oracle<4.15.0-1056.61~16.04.1
4.15.0-1056.61~16.04.1
ubuntu/linux-raspi2<4.4.0-1139.148
4.4.0-1139.148
ubuntu/linux-snapdragon<4.4.0-1143.152
4.4.0-1143.152
ubuntu/linux-hwe-edge*
ubuntu/linux-fips<4.4.0-1046.51
4.4.0-1046.51
ubuntu/linux-fips*
ubuntu/linux<4.15.0-121.123
4.15.0-121.123
ubuntu/linux-aws<4.15.0-1086.91
4.15.0-1086.91
ubuntu/linux-aws-5.4<5.4.0-1025.25~18.04.1
5.4.0-1025.25~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1099.110
4.15.0-1099.110
ubuntu/linux-azure-5.4<5.4.0-1026.26~18.04.1
5.4.0-1026.26~18.04.1
ubuntu/linux-gcp-4.15<4.15.0-1086.98
4.15.0-1086.98
ubuntu/linux-gcp-5.4<5.4.0-1025.25~18.04.1
5.4.0-1025.25~18.04.1
ubuntu/linux-gke-4.15<4.15.0-1072.76
4.15.0-1072.76
ubuntu/linux-hwe-5.4<5.4.0-48.52~18.04.1
5.4.0-48.52~18.04.1
ubuntu/linux-kvm<4.15.0-1077.79
4.15.0-1077.79
ubuntu/linux-oem<4.15.0-1099.109
4.15.0-1099.109
ubuntu/linux-oracle<4.15.0-1057.62
4.15.0-1057.62
ubuntu/linux-oracle-5.4<5.4.0-1025.25~18.04.1
5.4.0-1025.25~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1019.21~18.04.1
5.4.0-1019.21~18.04.1
ubuntu/linux-raspi2<4.15.0-1073.78
4.15.0-1073.78
ubuntu/linux-snapdragon<4.15.0-1089.98
4.15.0-1089.98
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-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-fips<4.15.0-2030.31
4.15.0-2030.31
ubuntu/linux-azure-fips<4.15.0-2012.14
4.15.0-2012.14
ubuntu/linux-fips<4.15.0-1044.50
4.15.0-1044.50
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.4.0-48.52
5.4.0-48.52
ubuntu/linux-aws<5.4.0-1025.25
5.4.0-1025.25
ubuntu/linux-azure<5.4.0-1026.26
5.4.0-1026.26
ubuntu/linux-gcp<5.4.0-1025.25
5.4.0-1025.25
ubuntu/linux-kvm<5.4.0-1024.24
5.4.0-1024.24
ubuntu/linux-oem-5.6<5.6.0-1048.52
5.6.0-1048.52
ubuntu/linux-oracle<5.4.0-1025.25
5.4.0-1025.25
ubuntu/linux-raspi<5.4.0-1019.21
5.4.0-1019.21
ubuntu/linux-riscv<5.4.0-34.38
5.4.0-34.38
ubuntu/linux-raspi2*
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*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/kernel-rt to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.11.1.rt56.1145.el7
  2. Upgrade

    Upgrade redhat/kernel-alt to a version that resolves this vulnerability.

    Fixed in 0:4.14.0-115.32.1.el7a
  3. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.11.1.el7
  4. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-693.82.1.el7
  5. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-957.70.1.el7
  6. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1062.45.1.el7
  7. Upgrade

    Upgrade redhat/kernel-rt to a version that resolves this vulnerability.

    Fixed in 0:4.18.0-305.rt7.72.el8
  8. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:4.18.0-305.el8
  9. Upgrade

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

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1
  10. Upgrade

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

    Fixed in 4.4.0-1078.82
  11. Upgrade

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

    Fixed in 4.15.0-1098.109~14.04.1
  12. Upgrade

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

    Fixed in 4.4.0-190.220~14.04.1
  13. Upgrade

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

    Fixed in 4.4.0-190.220
  14. Upgrade

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

    Fixed in 4.4.0-1114.127
  15. Upgrade

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

    Fixed in 4.15.0-1085.90~16.04.1
  16. Upgrade

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

    Fixed in 4.15.0-1098.109~16.04.1
  17. Upgrade

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

    Fixed in 4.15.0-1086.98~16.04.1
  18. Upgrade

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

    Fixed in 4.15.0-120.122~16.04.1
  19. Upgrade

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

    Fixed in 4.4.0-1080.87
  20. Upgrade

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

    Fixed in 4.15.0-1056.61~16.04.1
  21. Upgrade

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

    Fixed in 4.4.0-1139.148
  22. Upgrade

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

    Fixed in 4.4.0-1143.152
  23. Upgrade

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

    Fixed in 4.4.0-1046.51
  24. Upgrade

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

    Fixed in 4.15.0-121.123
  25. Upgrade

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

    Fixed in 4.15.0-1086.91
  26. Upgrade

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

    Fixed in 5.4.0-1025.25~18.04.1
  27. Upgrade

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

    Fixed in 4.15.0-1099.110
  28. Upgrade

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

    Fixed in 5.4.0-1026.26~18.04.1
  29. Upgrade

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

    Fixed in 4.15.0-1086.98
  30. Upgrade

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

    Fixed in 5.4.0-1025.25~18.04.1
  31. Upgrade

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

    Fixed in 4.15.0-1072.76
  32. Upgrade

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

    Fixed in 5.4.0-48.52~18.04.1
  33. Upgrade

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

    Fixed in 4.15.0-1077.79
  34. Upgrade

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

    Fixed in 4.15.0-1099.109
  35. Upgrade

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

    Fixed in 4.15.0-1057.62
  36. Upgrade

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

    Fixed in 5.4.0-1025.25~18.04.1
  37. Upgrade

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

    Fixed in 5.4.0-1019.21~18.04.1
  38. Upgrade

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

    Fixed in 4.15.0-1073.78
  39. Upgrade

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

    Fixed in 4.15.0-1089.98
  40. Upgrade

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

    Fixed in 4.15.0-2030.31
  41. Upgrade

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

    Fixed in 4.15.0-2012.14
  42. Upgrade

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

    Fixed in 4.15.0-1044.50
  43. Upgrade

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

    Fixed in 5.4.0-48.52
  44. Upgrade

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

    Fixed in 5.4.0-1025.25
  45. Upgrade

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

    Fixed in 5.4.0-1026.26
  46. Upgrade

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

    Fixed in 5.4.0-1025.25
  47. Upgrade

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

    Fixed in 5.4.0-1024.24
  48. Upgrade

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

    Fixed in 5.6.0-1048.52
  49. Upgrade

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

    Fixed in 5.4.0-1025.25
  50. Upgrade

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

    Fixed in 5.4.0-1019.21
  51. Upgrade

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

    Fixed in 5.4.0-34.38
  52. Upgrade

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

    Fixed in 5.4.0-1069.73+fips2
  53. Upgrade

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

    Fixed in 5.4.0-1073.76+fips1
  54. Upgrade

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

    Fixed in 5.4.0-1067.71~20.04.1
  55. Upgrade

    Upgrade Linux kernel to a version that resolves this vulnerability.

    Fixed in 5.8.3
  56. Compensating control

    Configure authentication and mount only authenticated NFSv4 servers to reduce exploitation risk.

Event History

Sep 9, 2020
CVE Published
12:00 AM
Data Sourced
via Ubuntu·12:00 AM
RemedyDescriptionSeverityAffected Software
CVE Published
via MITRE·03:52 PM
Data Sourced
via MITRE·03:52 PM
Description
Data Sourced
via OSV·04:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·08:57 PM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2020-25212?

CVE-2020-25212 has a high severity rating due to the potential for memory corruption and privilege escalation.

2

How do I fix CVE-2020-25212?

To fix CVE-2020-25212, update to the latest kernel versions provided in the remediation section for your specific distribution.

3

Which software is affected by CVE-2020-25212?

CVE-2020-25212 affects various versions of the Linux kernel, particularly those prior to version 5.8.3.

4

Can CVE-2020-25212 lead to a security risk?

Yes, CVE-2020-25212 can lead to significant security risks including unauthorized privilege escalation.

5

Is CVE-2020-25212 a remote attack vulnerability?

Yes, CVE-2020-25212 can be exploited by a remote attacker through specially crafted NFS requests.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203