{"cve":"CVE-2021-42306","nvd":{"published":"2021-11-24T01:15:08.363","modified":"2026-08-19T17:18:02.570","status":"Modified","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.","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:N","score":8.1},"cwes":["CWE-522"],"references":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42306","https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42306"],"products":["microsoft:azure_active_directory","microsoft:azure_active_site_recovery","microsoft:azure_automation","microsoft:azure_migrate"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-42306","score":0.03266,"percentile":0.8839,"date":"2026-11-01"},"kev":null,"osv":[],"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."]}