CVE-2021-3732

MEDIUMNVD 5.55.5—

5.5

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.

CVSS v3: 5.5
EG Score: 5.5(medium)
EPSS: 6.8%
KEV: Not listed

Published

March 10, 2022

Last Modified

November 21, 2024

References (8)

secalert@redhathttps://bugzilla.redhat.com/show_bug.cgi?id=1995249
secalert@redhathttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=427215d85e8d1476da1a86b8d67aceb485eb3631
secalert@redhathttps://github.com/torvalds/linux/commit/427215d85e8d1476da1a86b8d67aceb485eb3631
secalert@redhathttps://ubuntu.com/security/CVE-2021-3732
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.redhat.com/show_bug.cgi?id=1995249
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=427215d85e8d1476da1a86b8d67aceb485eb3631
af854a3a-2127-422b-91ae-364da2661108https://github.com/torvalds/linux/commit/427215d85e8d1476da1a86b8d67aceb485eb3631
af854a3a-2127-422b-91ae-364da2661108https://ubuntu.com/security/CVE-2021-3732

Patch Availability(12)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	linux-tools-azure (4.15.0.1124.97) @ trusty	2026-05-26	ubuntu
ubuntu	linux-image-raspi2 (4.15.0.1096.94) @ bionic	2026-05-26	ubuntu
ubuntu	linux-oem-20.04c (5.13.0.1014.18) @ focal	2026-05-26	ubuntu
ubuntu	linux-tools-oem-20.04-edge (5.10.0.1050.52) @ focal	2026-05-26	ubuntu
ubuntu	linux-image-lowlatency (5.4.0.89.93) @ focal	2026-05-26	ubuntu
ubuntu	linux-headers-5.11.0-1021-raspi (5.11.0-1021.22) @ hirsute	2026-05-26	ubuntu
ubuntu	linux-headers-5.4.0-1062-azure (5.4.0-1062.65) @ focal	2026-05-26	ubuntu
ubuntu	linux-image-4.4.0-1117-aws (4.4.0-1117.123) @ trusty	2026-05-26	ubuntu
ubuntu	linux-tools-4.4.0-239-lowlatency (4.4.0-239.273) @ xenial	2026-05-26	ubuntu
ubuntu	linux-tools-4.4.0-1155-aws (4.4.0-1155.170) @ xenial	2026-05-26	ubuntu
redhat	kernel-rt-0:4.18.0-348.rt7.130.el8	2021-11-09	redhat
redhat	kernel-0:4.18.0-348.el8	2021-11-09	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

All Vendor Advisories

(13)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-29 13:42 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-3732?

CVE-2021-3732 is a medium vulnerability published on March 10, 2022. 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.

When was CVE-2021-3732 disclosed?

CVE-2021-3732 was first published in the National Vulnerability Database on March 10, 2022, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-3732 actively exploited?

CVE-2021-3732 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-3732?

CVE-2021-3732 has a CVSS v3 base score of 5.5 (NVD).

How do I remediate CVE-2021-3732?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3732, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-3732

Published

Last Modified

References (8)

Patch Availability(12)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-3732?

Same vendor

Same CWE

CVE-2021-3732

📅 Published

🔄 Last Modified

🔗 References (8)

Patch Availability(12)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-3732?

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References (8)

Frequently asked(5)

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