CVE Vulnerability

CVE-2021-3493

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

7.2 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 10

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

Scope

7.8 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://www.openwall.com/lists/oss-security/2021/04/16/1 Mailing List Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52 Mailing List Patch
https://ubuntu.com/security/notices/USN-4917-1 Vendor Advisory
http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html Exploit Third Party Advisory
http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html Exploit Third Party Advisory
Configurations

Configuration 1

cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:-:*:*:*
Information

Published : 2021-04-17 05:15

Updated : 2022-10-27 12:43

NVD link : CVE-2021-3493

Mitre link : CVE-2021-3493

Products Affected
No products.
CWE
CWE-269