CVE-2021-22538

A privilege escalation vulnerability impacting the Google Exposure Notification Verification Server (versions prior to 0.23.1), allows an attacker who (1) has UserWrite permissions and (2) is using a carefully crafted request or malicious proxy, to create another user with higher privileges than their own. This occurs due to insufficient checks on the allowed set of permissions. The new user creation event would be captured in the Event Log.

• CWE-20
• CWE-276

• https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95Patch, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1Release Notes, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0Release Notes, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95Patch, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1Release Notes, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0Release Notes, Third Party Advisory
• https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6Third Party Advisory

Published

Mar 31, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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