CVE-2019-20794

MEDIUM

Linux Kernel 4.18-5.6.11 - Resource Exhaustion via FUSE Filesystem PID Namespace Termination

Title source: llm

Description

An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace, and mount a FUSE filesystem. Upon interaction with this FUSE filesystem, if the userspace component is terminated via a kill of the PID namespace's pid 1, it will result in a hung task, and resources being permanently locked up until system reboot. This can result in resource exhaustion.

References (4)

Core 4

Core References

Exploit, Third Party Advisory x_refsource_misc

https://github.com/sargun/fuse-example

View Exploit ZIP pw:eip

Exploit, Third Party Advisory x_refsource_misc

https://sourceforge.net/p/fuse/mailman/message/36598753/

Third Party Advisory x_refsource_confirm

https://security.netapp.com/advisory/ntap-20200608-0001/

Mailing List, Third Party Advisory mailing-list x_refsource_mlist

http://www.openwall.com/lists/oss-security/2020/08/24/1

Scores

CVSS v3 4.7

EPSS 0.0051

EPSS Percentile 39.3%

Attack Vector LOCAL

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

Details

CWE

CWE-772

Status published

Products (1)

linux/linux_kernel 4.18 - 5.6.11

Published May 09, 2020

Tracked Since Feb 18, 2026