A vulnerability classified as critical was found in Google Cloud Platform guest-oslogin up to 20200507 (Cloud Software). Affected by this vulnerability is some unknown functionality of the file roles/compute.osLogin. The manipulation with an unknown input leads to a default permission vulnerability. The CWE definition for the vulnerability is CWE-276. During installation, installed file permissions are set to allow anyone to modify those files. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was shared 06/22/2020 (GitHub Repository). It is possible to read the advisory at github.com. This vulnerability is known as CVE-2020-8903 since 02/12/2020. The exploitation appears to be difficult. Attacking locally is a requirement. A single authentication is required for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/23/2020). The attack technique deployed by this issue is T1222 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The entries 157160 and 157161 are related to this item.

Productinfo

Type

• Cloud Software

Vendor

• Google

Name

• Cloud Platform guest-oslogin

Version

• 20200507

License

• free

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CPE 2.2info

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• 🔍
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