CVE-2019-19447: Use After Free

Published Dec 8, 2019
·
Updated

A flaw was found in the Linux kernel's ext4unlink function. An attacker could corrupt memory or escalate privileges when deleting a file from a recently unmounted specially crafted ext4 filesystem, including local, USB, and iSCSI.

Other sources

A user with permissions to mount and unmount a crafted ext4 file system, via any transport mechanism (local, USB, ISCSI) can lead to a use-after-free when attempting to delete a directory after the disk has been umounted.

This can lead to possible memory corruption and privilege escalation.

External Reference:

https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19447 https://bugzilla.kernel.org/showbug.cgi?id=205433

— Red Hat

In the Linux kernel 5.0.21, mounting a crafted ext4 filesystem image, performing some operations, and unmounting can lead to a use-after-free in ext4putsuper in fs/ext4/super.c, related to dumporphanlist in fs/ext4/super.c.

Affected Software

74 affected componentsFixes available
redhat/kernel-rt<0:3.10.0-1160.rt56.1131.el7
0:3.10.0-1160.rt56.1131.el7
redhat/kernel-alt<0:4.14.0-115.21.2.el7a
0:4.14.0-115.21.2.el7a
redhat/kernel<0:3.10.0-1160.el7
0:3.10.0-1160.el7
redhat/kernel<0:3.10.0-693.81.1.el7
0:3.10.0-693.81.1.el7
redhat/kernel<0:3.10.0-957.65.1.el7
0:3.10.0-957.65.1.el7
redhat/kernel<0:3.10.0-1062.40.1.el7
0:3.10.0-1062.40.1.el7
redhat/kernel-rt<0:4.18.0-240.rt7.54.el8
0:4.18.0-240.rt7.54.el8
redhat/kernel<0:4.18.0-240.el8
0:4.18.0-240.el8
Linux Linux kernel>=2.6.12<3.16.82
Linux Linux kernel>=3.17<4.4.208
Linux Linux kernel>=4.5.0<4.9.208
Linux Linux kernel>=4.10<4.14.159
Linux Linux kernel>=4.15<4.19.90
Linux Linux kernel>=4.20<5.3.17
Linux Linux kernel>=5.4<5.4.4
NetApp Active Iq Unified Manager Vmware Vsphere
NetApp Cloud Backup
NetApp Data Availability Services
NetApp Hci Baseboard Management Controller=h610s
NetApp Steelstore Cloud Integrated Storage
NetApp Solidfire Baseboard Management Controller
ubuntu/linux-aws<4.4.0-1061.65
4.4.0-1061.65
ubuntu/linux-azure<4.15.0-1071.76~14.04.1
4.15.0-1071.76~14.04.1
ubuntu/linux-lts-xenial<4.4.0-173.203~14.04.1
4.4.0-173.203~14.04.1
ubuntu/linux*
ubuntu/linux<4.4.0-173.203
4.4.0-173.203
ubuntu/linux-aws<4.4.0-1101.112
4.4.0-1101.112
ubuntu/linux-aws-hwe<4.15.0-1060.62~16.04.1
4.15.0-1060.62~16.04.1
ubuntu/linux-azure<4.15.0-1071.76
4.15.0-1071.76
ubuntu/linux-gcp<4.15.0-1055.59
4.15.0-1055.59
ubuntu/linux-hwe<4.15.0-88.88~16.04.1
4.15.0-88.88~16.04.1
ubuntu/linux-kvm<4.4.0-1065.72
4.4.0-1065.72
ubuntu/linux-oracle<4.15.0-1033.36~16.04.1
4.15.0-1033.36~16.04.1
ubuntu/linux-raspi2<4.4.0-1128.137
4.4.0-1128.137
ubuntu/linux-snapdragon<4.4.0-1132.140
4.4.0-1132.140
ubuntu/linux-hwe-edge*
ubuntu/linux-fips<4.4.0-1028.33
4.4.0-1028.33
ubuntu/linux-fips*
ubuntu/linux<4.15.0-88.88
4.15.0-88.88
ubuntu/linux-aws<4.15.0-1060.62
4.15.0-1060.62
ubuntu/linux-aws-5.0<5.0.0-1025.28
5.0.0-1025.28
ubuntu/linux-azure<5.0.0-1032.34
5.0.0-1032.34
ubuntu/linux-azure-5.3<5.3.0-1013.14~18.04.1
5.3.0-1013.14~18.04.1
ubuntu/linux-gcp<5.0.0-1031.32
5.0.0-1031.32
ubuntu/linux-gcp-5.3<5.3.0-1012.13~18.04.1
5.3.0-1012.13~18.04.1
ubuntu/linux-gke-4.15<4.15.0-1052.55
4.15.0-1052.55
ubuntu/linux-gke-5.0<5.0.0-1030.31
5.0.0-1030.31
ubuntu/linux-gke-5.3<5.3.0-1012.13~18.04.1
5.3.0-1012.13~18.04.1
ubuntu/linux-hwe<5.3.0-40.32~18.04.1
5.3.0-40.32~18.04.1
ubuntu/linux-kvm<4.15.0-1053.53
4.15.0-1053.53
ubuntu/linux-oem<4.15.0-1073.83
4.15.0-1073.83
ubuntu/linux-oem-osp1<5.0.0-1039.44
5.0.0-1039.44
ubuntu/linux-oracle<4.15.0-1033.36
4.15.0-1033.36
ubuntu/linux-oracle-5.0<5.0.0-1011.16
5.0.0-1011.16
ubuntu/linux-raspi2<4.15.0-1055.59
4.15.0-1055.59
ubuntu/linux-raspi2-5.3<5.3.0-1018.20~18.04.1
5.3.0-1018.20~18.04.1
ubuntu/linux-snapdragon<4.15.0-1072.79
4.15.0-1072.79
ubuntu/linux-azure-edge*
ubuntu/linux-gcp-edge*
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-fips<4.15.0-2018.18
4.15.0-2018.18
ubuntu/linux-azure-fips<4.15.0-2006.7
4.15.0-2006.7
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1114.123~20.04.1
5.15.0-1114.123~20.04.1
ubuntu/linux-gke*
ubuntu/linux-raspi2*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-raspi-realtime*
ubuntu/linux-vmware*

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.rt56.1131.el7
  2. Upgrade

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

    Fixed in 0:4.14.0-115.21.2.el7a
  3. Upgrade

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

    Fixed in 0:3.10.0-1160.el7
  4. Upgrade

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

    Fixed in 0:3.10.0-693.81.1.el7
  5. Upgrade

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

    Fixed in 0:3.10.0-957.65.1.el7
  6. Upgrade

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

    Fixed in 0:3.10.0-1062.40.1.el7
  7. Upgrade

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

    Fixed in 0:4.18.0-240.rt7.54.el8
  8. Upgrade

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

    Fixed in 0:4.18.0-240.el8
  9. Upgrade

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

    Fixed in 4.4.0-1061.65
  10. Upgrade

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

    Fixed in 4.15.0-1071.76~14.04.1
  11. Upgrade

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

    Fixed in 4.4.0-173.203~14.04.1
  12. Upgrade

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

    Fixed in 4.4.0-173.203
  13. Upgrade

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

    Fixed in 4.4.0-1101.112
  14. Upgrade

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

    Fixed in 4.15.0-1060.62~16.04.1
  15. Upgrade

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

    Fixed in 4.15.0-1071.76
  16. Upgrade

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

    Fixed in 4.15.0-1055.59
  17. Upgrade

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

    Fixed in 4.15.0-88.88~16.04.1
  18. Upgrade

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

    Fixed in 4.4.0-1065.72
  19. Upgrade

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

    Fixed in 4.15.0-1033.36~16.04.1
  20. Upgrade

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

    Fixed in 4.4.0-1128.137
  21. Upgrade

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

    Fixed in 4.4.0-1132.140
  22. Upgrade

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

    Fixed in 4.4.0-1028.33
  23. Upgrade

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

    Fixed in 4.15.0-88.88
  24. Upgrade

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

    Fixed in 4.15.0-1060.62
  25. Upgrade

    Upgrade ubuntu/linux-aws-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1025.28
  26. Upgrade

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

    Fixed in 5.0.0-1032.34
  27. Upgrade

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

    Fixed in 5.3.0-1013.14~18.04.1
  28. Upgrade

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

    Fixed in 5.0.0-1031.32
  29. Upgrade

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

    Fixed in 5.3.0-1012.13~18.04.1
  30. Upgrade

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

    Fixed in 4.15.0-1052.55
  31. Upgrade

    Upgrade ubuntu/linux-gke-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1030.31
  32. Upgrade

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

    Fixed in 5.3.0-1012.13~18.04.1
  33. Upgrade

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

    Fixed in 5.3.0-40.32~18.04.1
  34. Upgrade

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

    Fixed in 4.15.0-1053.53
  35. Upgrade

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

    Fixed in 4.15.0-1073.83
  36. Upgrade

    Upgrade ubuntu/linux-oem-osp1 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1039.44
  37. Upgrade

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

    Fixed in 4.15.0-1033.36
  38. Upgrade

    Upgrade ubuntu/linux-oracle-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1011.16
  39. Upgrade

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

    Fixed in 4.15.0-1055.59
  40. Upgrade

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

    Fixed in 5.3.0-1018.20~18.04.1
  41. Upgrade

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

    Fixed in 4.15.0-1072.79
  42. Upgrade

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

    Fixed in 4.15.0-2018.18
  43. Upgrade

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

    Fixed in 4.15.0-2006.7
  44. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.123~20.04.1
  45. Compensating control

    Disallow mounting of untrusted ext4 filesystems and remove users' ability to mount and unmount filesystems, including those delivered via local, USB, or iSCSI transports.

Event History

Dec 8, 2019
CVE Published
via MITRE·12:48 AM
Data Sourced
via MITRE·12:48 AM
Description
Data Sourced
via OSV·01:15 AM
DescriptionSeverityAffected Software
Dec 10, 2019
Data Sourced
via Red Hat·11:37 AM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is CVE-2019-19447?

CVE-2019-19447 is a vulnerability in the Linux kernel's ext4_unlink function that allows an attacker to corrupt memory or escalate privileges when deleting a file from a specially crafted ext4 filesystem.

2

How severe is CVE-2019-19447?

CVE-2019-19447 has a severity rating of 7.8, which is considered high.

3

Which software versions are affected by CVE-2019-19447?

CVE-2019-19447 affects Linux kernel versions 5.0.21 and earlier.

4

How can I fix CVE-2019-19447?

To fix CVE-2019-19447, you should update your affected Linux kernel to version 5.0.22 or later.

5

Are there any references for CVE-2019-19447?

Yes, you can find more information about CVE-2019-19447 on the following links: [link1](https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19447), [link2](https://bugzilla.kernel.org/show_bug.cgi?id=205433), [link3](https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1781680).

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