CVE-2021-3492

high
New! CVE Severity Now Using CVSS v3

The calculated severity for CVEs has been updated to use CVSS v3 by default. CVEs that do not have a CVSS v3 score will fall back CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

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.

References

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

Details

Source: MITRE

Published: 2021-04-17

Updated: 2021-05-21

Type: CWE-415

Risk Information

CVSS v2

Base Score: 7.2

Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Impact Score: 10

Exploitability Score: 3.9

Severity: HIGH

CVSS v3

Base Score: 7.8

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

Impact Score: 5.9

Exploitability Score: 1.8

Severity: HIGH

Tenable Plugins

View all (2 total)

IDNameProductFamilySeverity
148690Ubuntu 18.04 LTS / 20.04 LTS / 20.10 : Linux kernel vulnerabilities (USN-4917-1)NessusUbuntu Local Security Checks
high
148689Ubuntu 20.04 LTS : Linux kernel (OEM) vulnerabilities (USN-4915-1)NessusUbuntu Local Security Checks
high