CVE-2021-3492

HIGH

Canonical Ubuntu Linux < 18.04 - Memory Leak

Title source: rule

Description

Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562.

Exploits (1)

nomisec WORKING POC 42 stars

by synacktiv · poc

https://github.com/synacktiv/CVE-2021-3492

View Code ZIP pw:eip

References (6)

[Third Party Advisory, VDB Entry] http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html

[Mailing List, Patch, Vendor Advisory] https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333

[Mailing List, Patch, Vendor Advisory] https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6

[Vendor Advisory] https://ubuntu.com/security/notices/USN-4917-1

[Mailing List, Third Party Advisory] https://www.openwall.com/lists/oss-security/2021/04/16/2

[Third Party Advisory, VDB Entry] https://www.zerodayinitiative.com/advisories/ZDI-21-422/

Scores

CVSS v3 8.8

EPSS 0.2444

EPSS Percentile 96.0%

Attack Vector LOCAL

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Classification

CWE

CWE-415 CWE-401

Status published

Affected Products (2)

canonical/ubuntu_linux < 18.04

canonical/ubuntu_linux < 20.10

Timeline

Published Apr 17, 2021

Tracked Since Feb 18, 2026