CVE-2020-8903Public exploit

Root escalation via metadata server impersonation

Published Jun 22, 2020 · Updated Aug 4, 2024

Privilege escalation in Google OS Login Guest Environment 20190304 through 20200506 allows local users with OS Login access to gain root. Default OS Login configuration adds non-admin users to adm, exposing the DHCP XID in the systemd journal; the XID enables hostname changes that redirect metadata.google.internal to an impersonated metadata server. The attacker needs roles/compute.osLogin on a VM with OS Login enabled, and a forged adminLogin response causes pam_oslogin_admin.so to grant sudo privileges.

CVSS severity7.3
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Privilege escalation in Google OS Login Guest Environment 20190304 through 20200506 allows local users with OS Login access to gain root. Default OS Login configuration adds non-admin users to adm, exposing the DHCP XID in the systemd journal; the XID enables hostname changes that redirect metadata.google.internal to an impersonated metadata server. The attacker needs roles/compute.osLogin on a VM with OS Login enabled, and a forged adminLogin response causes pam_oslogin_admin.so to grant sudo privileges.

The record

CVE
CVE-2020-8903
Published
Jun 22, 2020
Updated
Aug 4, 2024
Vendor
Google
Product
OS Login Guest Environment
Classifications
CWE-276, T1548.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 22, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=20190304 <20200507

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · OS Login Guest Environmentversion=20190304 <20200507

Published CVSS scores

7.3GoogleCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
6.9NIST NVDAV:L/AC:M/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1548.003Sudo and Sudo Caching

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo