{"id":"CVE-2021-42306","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-42306","generatedAt":"2026-10-27T19:57:33.005Z","title":"An information disclosure vulnerability manifests when a user or an application uploads unprotected private key data as part of an authentication certificate keyCredential on an Azure AD Application or Service Principal (which is not recommended).","description":"An information disclosure vulnerability manifests when a user or an application uploads unprotected private key data as part of an authentication certificate keyCredential  on an Azure AD Application or Service Principal (which is not recommended). This vulnerability allows a user or service in the tenant with application read access to read the private key data that was added to the application.\nAzure AD addressed this vulnerability by preventing disclosure of any private key values added to the application.\nMicrosoft has identified services that could manifest this vulnerability, and steps that customers should take to be protected. Refer to the FAQ section for more information.\nFor more details on this issue, please refer to the MSRC Blog Entry.","published":"2021-11-24T01:15:08.000Z","lastModified":"2026-08-19T17:18:03.000Z","status":"Modified","sourceIdentifier":"secure@microsoft.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-522"],"affected":["microsoft/azure active directory","microsoft/azure active site recovery","microsoft/azure automation","microsoft/azure migrate"],"epss":{"score":0.03266,"percentile":0.88303,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (3.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42306","source":"secure@microsoft.com"},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42306","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-42306","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}