# CVE-2024-27086: MSAL.NET applications targeting Xamarin Android and .NET Android (MAUI) susceptible to local denial of service

> A malicious Android app can cause denial of service in MSAL.NET apps by exploiting incorrect activity export configurations, preventing user login.

- **Severity:** Low 3.9 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 16 Apr 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-x674-v45j-fwxw

## What is CVE-2024-27086?

CVE-2024-27086 is a low-severity vulnerability in AzureAD microsoft-authentication-library-for-dotnet, published on 16 Apr 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

The MSAL library enabled acquisition of security tokens to call protected APIs. MSAL.NET applications targeting Xamarin Android and .NET Android (e.g., MAUI) using the library from versions 4.48.0 to 4.60.0 are impacted by a low severity vulnerability.   
A malicious application running on a customer Android device    can cause local denial of service against applications that were built using MSAL.NET for authentication on the same device (i.e., prevent the user of the legitimate application from logging in) due to incorrect activity export configuration. MSAL.NET version 4.60.1 includes the fix.  As a workaround, a developer may explicitly mark the MSAL.NET activity non-exported.

Weakness: CWE-926 (Improper Export of Android Application Components), CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2024-27086?

4 open source packages ship an affected version, including Microsoft.Identity.Client.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Microsoft.Identity.Client` | NuGet | From 4.48.0 | 4.59.1 |
| `Microsoft.Identity.Client` | NuGet | From 4.48.0 | 4.59.1 |
| `Microsoft.Identity.Client` | NuGet | From 4.60.0 | 4.60.3 |
| `Microsoft.Identity.Client` | NuGet | From 4.60.0 | 4.60.3 |

## How do I fix CVE-2024-27086?

Upgrade Microsoft.Identity.Client to a fixed version for your release line: 4.59.1 or 4.60.3.

## Is CVE-2024-27086 being exploited?

There is no known exploitation of CVE-2024-27086 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-27086 and fix it if it is affected.

What it is: CVE-2024-27086 is a low-severity vulnerability in AzureAD microsoft-authentication-library-for-dotnet, published on 16 Apr 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-27086 in the wild and no public exploit code.

Affected packages and fixed versions:
- Microsoft.Identity.Client (NuGet): affected from 4.48.0; fixed in 4.59.1
- Microsoft.Identity.Client (NuGet): affected from 4.48.0; fixed in 4.59.1
- Microsoft.Identity.Client (NuGet): affected from 4.60.0; fixed in 4.60.3
- Microsoft.Identity.Client (NuGet): affected from 4.60.0; fixed in 4.60.3

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-2024-27086/ (Markdown: https://insights.sbomify.com/CVE-2024-27086/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27086
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27086
- OSV: https://osv.dev/vulnerability/CVE-2024-27086

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27086/
Summaries are generated and may contain mistakes; the official description above is the record.