{"id":"CVE-2021-22538","aliases":["GHSA-5v95-v8c8-3rh6","GO-2022-0798"],"title":"Privilege escalation in rbac","summary":"Privilege escalation in rbac","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"google","product":"github.com/google/exposure-notifications-verification-server","ecosystem":"go","affected":["github.com/google/exposure-notifications-verification-server < 0.23.1"],"patched":["github.com/google/exposure-notifications-verification-server 0.23.1"],"published":"2021-05-21","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-5v95-v8c8-3rh6","references":[{"url":"https://github.com/google/exposure-notifications-verification-server/security/advisories/GHSA-5v95-v8c8-3rh6"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22538"},{"url":"https://github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12dbe79304f1133c06fb73419383cd95"},{"url":"https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.23.1"},{"url":"https://github.com/google/exposure-notifications-verification-server/releases/tag/v0.24.0"}],"tags":["osv","go"],"epss":0.00718,"epssPercentile":0.51773,"ingestedAt":"2026-07-09T18:56:35.950Z","slug":"CVE-2021-22538","body":"## Overview\n\n### Impact\nUsing a carefully crafted request or malicious proxy, a user with `UserWrite` permissions could create another user with higher privileges than their own due to insufficient checks on the allowed set of permissions. The event would be captured in the Event Log.\n\n### Patches\nThe issue has been fixed in 0.24.0 and 0.23.1.\n\n### Workarounds\nFor users who are unable to upgrade, we recommend auditing users who have `UserWrite` permissions and regularly reviewing the Event Log for malicious activity.\n\n### Kudos\nThank you to Michael Mazzolini (Ethical Hacker at WHO) for finding and disclosing this vulnerability.\n\n## Affected packages\n\n- `github.com/google/exposure-notifications-verification-server < 0.23.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/google/exposure-notifications-verification-server 0.23.1`","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}