CVE-2021-3492 Information

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.

CVSS Vector

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

Reference

https://www.openwall.com/lists/oss-security/2021/04/16/2 https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333 https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6 https://ubuntu.com/security/notices/USN-4917-1 https://www.zerodayinitiative.com/advisories/ZDI-21-422/ http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8