CVE-2019-19922 Information

Description

kernel/sched/fair.c in the Linux kernel before 5.3.9 when cpu.cfs_quota_us is used (e.g. with Kubernetes) allows attackers to cause a denial of service against non-cpu-bound applications by generating a workload that triggers unwanted slice expiration aka CID-de53fd7aedb1. (In other words although this slice expiration would typically be seen with benign workloads it is possible that an attacker could calculate how many stray requests are required to force an entire Kubernetes cluster into a low-performance state caused by slice expiration and ensure that a DDoS attack sent that number of stray requests. An attack does not affect the stability of the kernel; it only causes mismanagement of application execution.)

CVSS Vector

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

Reference

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.9 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=de53fd7aedb100f03e5d2231cfce0e4993282425 https://github.com/kubernetes/kubernetes/issues/67577 https://github.com/torvalds/linux/commit/de53fd7aedb100f03e5d2231cfce0e4993282425 https://lists.debian.org/debian-lts-announce/2020/01/msg00013.html https://relistan.com/the-kernel-may-be-slowing-down-your-app https://security.netapp.com/advisory/ntap-20200204-0002/ https://usn.ubuntu.com/4226-1/

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.5