CVE-2019-11833: Infoleak

Published May 11, 2019
·
Updated

A flaw was found in the Linux kernel's implementation of ext4 extent management. The kernel doesn't correctly initialize memory regions in the extent tree block which may be exported to a local user to obtain sensitive information by reading empty/uninitialized data from the filesystem.

Other sources

A flaw was found in the Linux kernels implementation of ext4 extent management which did not correctly initialize memory regions in the extent tree block which may be exported to a local user to obtain sensitive information by reading empty/uninitialized data from the filesystem.

This is considered an information leak, but the information leveraged could be used in to future another attack.

Upstream patch:

https://github.com/torvalds/linux/commit/592acbf16821288ecdc4192c47e3774a4c48bb64

Red Hat

fs/ext4/extents.c in the Linux kernel through 5.1.2 does not zero out the unused memory region in the extent tree block, which might allow local users to obtain sensitive information by reading uninitialized data in the filesystem.

Affected Software

38 affected componentsFixes available
redhat/kernel-rt<0:3.10.0-1062.rt56.1022.el7
0:3.10.0-1062.rt56.1022.el7
redhat/kernel<0:3.10.0-1062.el7
0:3.10.0-1062.el7
redhat/kernel-rt<0:4.18.0-147.rt24.93.el8
0:4.18.0-147.rt24.93.el8
redhat/kernel<0:4.18.0-147.el8
0:4.18.0-147.el8
Google Android
Linux Linux kernel<=5.1.2
Fedoraproject Fedora=29
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=19.04
redhat Enterprise Linux=8.0
redhat Enterprise Linux Desktop=7.0
redhat Enterprise Linux Eus=8.1
redhat Enterprise Linux Eus=8.2
redhat Enterprise Linux Eus=8.4
redhat Enterprise Linux Eus=8.6
redhat Enterprise Linux For Real Time=7
redhat Enterprise Linux For Real Time=8.0
redhat Enterprise Linux For Real Time For Nfv=7
redhat Enterprise Linux For Real Time For Nfv=8.0
redhat Enterprise Linux For Real Time For Nfv Tus=8.2
redhat Enterprise Linux For Real Time For Nfv Tus=8.4
redhat Enterprise Linux For Real Time For Nfv Tus=8.6
redhat Enterprise Linux For Real Time Tus=8.2
redhat Enterprise Linux For Real Time Tus=8.4
redhat Enterprise Linux For Real Time Tus=8.6
redhat Enterprise Linux Server=7.0
redhat Enterprise Linux Server Aus=8.2
redhat Enterprise Linux Server Aus=8.4
redhat Enterprise Linux Server Aus=8.6
redhat Enterprise Linux Server Tus=8.2
redhat Enterprise Linux Server Tus=8.4
redhat Enterprise Linux Server Tus=8.6
redhat Enterprise Linux Workstation=7.0
debian/linux
5.10.223-15.10.262-16.1.176-16.1.180-16.12.94-16.12.101-17.1.8-17.1.8-2

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 0:3.10.0-1062.rt56.1022.el7
  2. Upgrade

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

    Fixed in 0:3.10.0-1062.el7
  3. Upgrade

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

    Fixed in 0:4.18.0-147.rt24.93.el8
  4. Upgrade

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

    Fixed in 0:4.18.0-147.el8
  5. Upgrade

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

    Fixed in 5.10.223-1Fixed in 5.10.262-1Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.101-1Fixed in 7.1.8-1Fixed in 7.1.8-2
  6. Upgrade

    Upgrade Linux kernel (ext4) to a version that resolves this vulnerability.

    Fixed in 5.1.2

Event History

May 11, 2019
CVE Published
12:00 AM
May 15, 2019
CVE Published
via MITRE·12:19 PM
Data Sourced
via MITRE·12:19 PM
Description
Data Sourced
via NVD·01:29 PM
RemedyDescriptionSeverityWeaknessAffected Software
May 20, 2019
Data Sourced
via Red Hat·05:41 PM
DescriptionSeverityAffected Software
Jun 24, 2026
Data Sourced
via Launchpad·10:21 AM
Description
Aug 15, 2026
Data Sourced
via Ubuntu·11:19 AM
RemedyDescriptionSeverityAffected Software
Aug 16, 2026
Data Sourced
via Debian·11:21 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2019-11833?

CVE-2019-11833 is classified as a medium severity vulnerability affecting the Linux kernel's ext4 filesystem.

2

How do I fix CVE-2019-11833?

To fix CVE-2019-11833, update your system to the patched versions of the Linux kernel provided by your distribution.

3

Which systems are affected by CVE-2019-11833?

CVE-2019-11833 affects various distributions of the Linux kernel including specific versions for Red Hat, Debian, and Ubuntu.

4

What type of vulnerability is CVE-2019-11833?

CVE-2019-11833 is a memory initialization flaw that may allow local users to read uninitialized data from the filesystem.

5

Is CVE-2019-11833 exploitable remotely?

CVE-2019-11833 is not exploitable remotely; it requires local access to the affected system.

Contact

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