Vulnerability in Microsoft Azure Active Directory

CVE-2021-42306

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. Azure AD addressed this vulnerability by preventing disclosure of any private key values added to the application. Microsoft 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. For more details on this issue, please refer to the MSRC Blog Entry.

EPSS: 0.031 (86.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-42306?
CVE-2021-42306 is a high-severity vulnerability in Microsoft Azure Active Directory, classified under Insufficiently Protected Credentials. CVSS score: 8.1/10. Published 2021-11-24.
How severe is CVE-2021-42306?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2021-42306 known to be exploited?
5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.