CVE-2020-8903 Priviged Escalation in Google Cloud Platform's Guest-OSLogin
Attackers with OS Login role can escalate to root by impersonating the metadata server via DHCP XID manipulation in GCP instances.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2020-8903?
CVE-2020-8903 is a high-severity vulnerability in Opensuse Leap, published on 22 Jun 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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 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.
Weakness: CWE-276
Which versions are affected by CVE-2020-8903?
It affects 2 products.
Products include Google Guest-Oslogin, Opensuse Leap.
How do I fix CVE-2020-8903?
Upgrade to a fixed version.
Is CVE-2020-8903 being exploited?
There is no known exploitation of CVE-2020-8903 in the wild and no public exploit code.
Other vulnerabilities in Opensuse Leap
Sources
Also known as GHSA-29mh-jw46-2rf9, UBUNTU-CVE-2020-8903.