CVE-2020-8903

Publication date 22 June 2020

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.8 · High

Score breakdown

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.

Status

Package Ubuntu Release Status
gce-compute-image-packages 25.04 plucky
Fixed 20190801-0ubuntu5
24.10 oracular
Fixed 20190801-0ubuntu5
24.04 LTS noble
Fixed 20190801-0ubuntu5
23.10 mantic
Fixed 20190801-0ubuntu5
23.04 lunar
Fixed 20190801-0ubuntu5
22.10 kinetic
Fixed 20190801-0ubuntu5
22.04 LTS jammy
Fixed 20190801-0ubuntu5
21.10 impish
Fixed 20190801-0ubuntu5
21.04 hirsute
Fixed 20190801-0ubuntu5
20.10 groovy
Fixed 20190801-0ubuntu5
20.04 LTS focal
Fixed 20190801-0ubuntu4.1
19.10 eoan
Fixed 20190801-0ubuntu1.1
18.04 LTS bionic
Fixed 20190801-0ubuntu1~18.04.1
16.04 LTS xenial
Fixed 20190801-0ubuntu1~16.04.1
14.04 LTS trusty
Vulnerable

Severity score breakdown

Parameter Value
Base score 7.8 · High
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H