# CVE-2021-42306: Azure Active Directory Information Disclosure Vulnerability

> Attackers with application read access can view private keys uploaded to Azure AD applications, exposing sensitive authentication credentials.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Nov 2021
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-vxjx-p5m9-q5fr

## What is CVE-2021-42306?

CVE-2021-42306 is a high-severity vulnerability in Microsoft Azure Active Directory, published on 24 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.
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.

Weakness: CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2021-42306?

It affects 4 products.


Products: Microsoft Azure Active Directory, Microsoft Azure Active Site Recovery, Microsoft Azure Automation, Microsoft Azure Migrate.

## How do I fix CVE-2021-42306?

No fix has been published for CVE-2021-42306 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42306 being exploited?

There is no known exploitation of CVE-2021-42306 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Azure Active Directory

- [CVE-2026-45480](https://insights.sbomify.com/CVE-2026-45480/): Azure Active Directory Elevation of Privilege Vulnerability (critical 10.0)
- [CVE-2026-50481](https://insights.sbomify.com/CVE-2026-50481/): Azure Active Directory Elevation of Privilege Vulnerability (critical 9.9)
- [CVE-2024-21381](https://insights.sbomify.com/CVE-2024-21381/): Microsoft Azure Active Directory B2C Spoofing Vulnerability (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42306 and fix it if it is affected.

What it is: CVE-2021-42306 is a high-severity vulnerability in Microsoft Azure Active Directory, published on 24 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-42306 in the wild and no public exploit code.

Affected product: Microsoft Azure Active Directory. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-42306/ (Markdown: https://insights.sbomify.com/CVE-2021-42306/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42306
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42306
- OSV: https://osv.dev/vulnerability/CVE-2021-42306

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-42306/
Summaries are generated and may contain mistakes; the official description above is the record.