Vulnerability 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 their membership to the "adm" group, users with this role are able to read the DHCP XID from the systemd journal. Using the DHCP XID, it is then possible to set the IP address and hostname of the instance to any value, which is then stored in /etc/hosts. An attacker can then point metadata.google.internal to an arbitrary IP address and impersonate the GCE metadata server which make it is possible to instruct the OS Login PAM module to grant 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 "adm" user from the OS Login entry.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Guest-Oslogin | >= 20190304.00, <= 20200507.00 | |
| Opensuse | Leap | 15.1 |
Related Weaknesses (CWE)
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00037.htmlMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00047.htmlMailing ListThird Party Advisory
- https://cloud.google.com/support/bulletins/#gcp-2020-008Vendor Advisory
- https://github.com/GoogleCloudPlatform/guest-oslogin/pull/29PatchThird Party Advisory
- https://gitlab.com/gitlab-com/gl-security/gl-redteam/red-team-tech-notes/-/tree/ExploitThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00037.htmlMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00047.htmlMailing ListThird Party Advisory
- https://cloud.google.com/support/bulletins/#gcp-2020-008Vendor Advisory
- https://github.com/GoogleCloudPlatform/guest-oslogin/pull/29PatchThird Party Advisory
- https://gitlab.com/gitlab-com/gl-security/gl-redteam/red-team-tech-notes/-/tree/ExploitThird Party Advisory
FAQ
What is CVE-2020-8903?
CVE-2020-8903 is a vulnerability with a CVSS score of 7.8 (HIGH). 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. Usin...
How severe is CVE-2020-8903?
CVE-2020-8903 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-8903?
Check the references section above for vendor advisories and patch information. Affected products include: Google Guest-Oslogin, Opensuse Leap.