CVE-2021-3732: Infoleak

Published Aug 12, 2021
·
Updated

A flaw was found in the Linux kernel's OverlayFS subsystem in the way the user mounts the TmpFS filesystem with OverlayFS. This flaw allows a local user to gain access to hidden files that should not be accessible.

Other sources

A flaw was found in the Linux kernel’s OverlayFS subsystem in the way the user mounts the TmpFS filesystem with OverlayFS. This flaw allows a local user to gain access to hidden files that should not be accessible.

A flaw was found in the Linux kernels implementation of overlayfs where a local attacker with an unpriviledged account who has the ability to mount a filesystem can abuse a logic bug in the overlayfs code which can inadvertantly reveal files hidden in the orignal mount.

References:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=427215d85e8d https://bugzilla.redhat.com/showbug.cgi?id=1993131

Red Hat

Affected Software

11 affected componentsFixes available
redhat/kernel-rt<0:4.18.0-348.rt7.130.el8
0:4.18.0-348.rt7.130.el8
redhat/kernel<0:4.18.0-348.el8
0:4.18.0-348.el8
redhat/kernel<5.14
5.14
Linux Linux kernel<5.14
Linux Linux kernel=5.14
Linux Linux kernel=5.14-rc1
Linux Linux kernel=5.14-rc2
Linux Linux kernel=5.14-rc3
Linux Linux kernel=5.14-rc4
Linux Linux kernel=5.14-rc5
debian/linux
5.10.223-15.10.251-16.1.159-16.1.164-16.12.73-16.12.74-26.19.6-2

Remediation

Information

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Event History

Aug 12, 2021
CVE Published
12:00 AM
Mar 7, 2022
CVE Published
via MITRE·01:56 PM
Data Sourced
via MITRE·01:56 PM
DescriptionWeakness
Jan 11, 2024
Data Sourced
via Launchpad·11:58 PM
Description
Mar 7, 2026
Data Sourced
via Ubuntu·09:24 PM
RemedyDescriptionSeverityAffected Software
Mar 14, 2026
Data Sourced
via Debian·09:30 PM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2021-3732?

CVE-2021-3732 is classified as a medium severity vulnerability.

2

How do I fix CVE-2021-3732?

To fix CVE-2021-3732, update the kernel package to the recommended versions provided by your Linux distribution.

3

Who is affected by CVE-2021-3732?

CVE-2021-3732 affects users of certain versions of the Linux kernel, specifically those utilizing OverlayFS functionality.

4

What is the impact of CVE-2021-3732?

The impact of CVE-2021-3732 is that a local user may gain unauthorized access to hidden files.

5

Is CVE-2021-3732 being actively exploited?

As of now, there is no public information indicating that CVE-2021-3732 is actively being exploited in the wild.

Contact

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