{"cve":"CVE-2021-22538","nvd":{"published":"2021-03-31T21:15:16.057","modified":"2026-06-17T03:37:24.067","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-276","CWE-20"],"references":["https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95","https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1","https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0","https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6","https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95"],"products":["google:exposure_notifications_verification_server"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-22538","score":0.00718,"percentile":0.53859,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5v95-v8c8-3rh6","url":"https://osv.dev/vulnerability/GHSA-5v95-v8c8-3rh6","summary":"Privilege escalation in rbac","modified":"2026-07-08T06:29:54.377303904Z","packages":[{"ecosystem":"Go","name":"github.com/google/exposure-notifications-verification-server","purl":"pkg:golang/github.com/google/exposure-notifications-verification-server","ranges":["<0.23.1"],"fixed":["0.23.1"]}]},{"id":"GO-2022-0798","url":"https://osv.dev/vulnerability/GO-2022-0798","summary":"Privilege escalation in rbac in github.com/google/exposure-notifications-verification-server","modified":"2026-03-03T04:52:15.572098Z","packages":[{"ecosystem":"Go","name":"github.com/google/exposure-notifications-verification-server","purl":"pkg:golang/github.com/google/exposure-notifications-verification-server","ranges":["<0.23.1"],"fixed":["0.23.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}