CVE-2021-3732

kernel: overlayfs: Mounting overlayfs inside an unprivileged user namespace can reveal files

Severity Score

5.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Se ha encontrado un fallo en el subsistema OverlayFS del kernel de Linux en la forma en que el usuario monta el sistema de archivos TmpFS con OverlayFS. Este fallo permite a un usuario local acceder a archivos ocultos que no deberían ser accesibles

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.

*Credits: N/A

CVSS Scores

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-08-23 CVE Reserved
2021-09-28 CVE Published
2023-03-08 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

CAPEC

References (5)

URL	Tag	Source
https://ubuntu.com/security/CVE-2021-3732	Third Party Advisory

URL	Date	SRC

URL	Date	SRC
https://bugzilla.redhat.com/show_bug.cgi?id=1995249	2021-11-09
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=427215d85e8d1476da1a86b8d67aceb485eb3631	2022-12-13
https://github.com/torvalds/linux/commit/427215d85e8d1476da1a86b8d67aceb485eb3631	2022-12-13

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2021-3732	2021-11-09

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.14 Search vendor "Linux" for product "Linux Kernel" and version " < 5.14"		-		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		-		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		rc1		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		rc2		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		rc3		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		rc4		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.14 Search vendor "Linux" for product "Linux Kernel" and version "5.14"		rc5		Affected