Vulnerability · Published Jun 22, 2020 · Assigned by Google
CVE-2020-8933Priviged Escalation in Google Cloud Platform's Guest-OSLogin
Critical 9.3
In plain English
A critical-severity incorrect default permissions in guest-oslogin from Google LLC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Google LLC | guest-oslogin | 20190304 – before 20200507 |
Weakness: CWE-276 · 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
References
- https://github.com/GoogleCloudPlatform/guest-oslogin/pull/29 x_refsource_CONFIRM
- https://gitlab.com/gitlab-com/gl-security/gl-redteam/red-team-tech-notes/-/tree/master/oslogin-privesc-june-2020 x_refsource_MISC
- https://cloud.google.com/support/bulletins/#gcp-2020-008 x_refsource_MISC
- openSUSE-SU-2020:0996 vendor-advisory, x_refsource_SUSE
- openSUSE-SU-2020:1014 vendor-advisory, x_refsource_SUSE