Cyber Resilience

CVE-2021-42306

High

Published: 24 November 2021

Published
24 November 2021
Modified
24 February 2026
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0824 92.4th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42306 is a high-severity Insufficiently Protected Credentials (CWE-522) vulnerability in Microsoft Azure Active Directory. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 7.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
azure active directory
≤ 2021-10-30
microsoft
azure active site recovery
≤ 2021-11-01
microsoft
azure automation
≤ 2021-10-15
microsoft
azure migrate
≤ 2021-11-02

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-522

Training instructs users on protecting credentials from disclosure or unauthorized access.

addresses: CWE-522

Training records for security awareness and role-based training verify education on credential protection practices, tangibly reducing risks from mishandling or exposing credentials.

addresses: CWE-522

Protecting authenticator content from unauthorized disclosure and modification while requiring protective controls addresses insufficiently protected credentials.

addresses: CWE-522

Rules of behavior include credential protection and non-sharing requirements, reducing exposure of insufficiently protected credentials.

addresses: CWE-522

Terminating or revoking credentials stops use of insufficiently protected or lingering credentials post-termination.

addresses: CWE-522

Requiring confidentiality/integrity protection for stored credentials directly mitigates insufficiently protected credentials on disk or in configuration stores.

addresses: CWE-522

Credentials or keys delivered out-of-band are not exposed to interception or inadequate protection on the main transport.

References