CVE-2024-27086

MSAL.NET applications targeting Xamarin Android and .NET Android (MAUI) susceptible to local denial of service

<activity android:name="microsoft.identity.client.AuthenticationAgentActivity" android:configChanges="orientation|screenSize" android:exported="false">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="msalYOUR_CLIENT_ID" android:host="auth" />
</intent-filter>
</activity>

MSAL.NET applications targeting Xamarin Android and .NET Android (e.g., MAUI) using the library from versions 4.48.0 to 4.60.3 (inclusive, except 4.59.1 and 4.60.3) are impacted by a low severity vulnerability.

A malicious application running on a customer Android device can (1) inject HTML/JavaScript in an embedded web view exported by affected applications, or (2) 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.

The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.

CVE-2024-27086 has a CVSS score of 3.9 (Low). The vector is requires local access, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.59.1, 4.60.3); upgrading removes the vulnerable code path.

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MSAL.NET version 4.60.3 includes the fix. We recommend all users of MSAL.NET that are building public client applications for Android update to the latest version.

1. What is CVE-2024-27086? CVE-2024-27086 is a low-severity incorrect authorization vulnerability in Microsoft.Identity.Client (nuget), affecting versions >= 4.48.0, < 4.59.1. It is fixed in 4.59.1, 4.60.3. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
2. How severe is CVE-2024-27086? CVE-2024-27086 has a CVSS score of 3.9 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of Microsoft.Identity.Client are affected by CVE-2024-27086? Microsoft.Identity.Client (nuget) versions >= 4.48.0, < 4.59.1 is affected.
4. Is there a fix for CVE-2024-27086? Yes. CVE-2024-27086 is fixed in 4.59.1, 4.60.3. Upgrade to this version or later.
5. Is CVE-2024-27086 exploitable, and should I be worried? Whether CVE-2024-27086 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-27086 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-27086?
   • Upgrade Microsoft.Identity.Client to 4.59.1 or later
   • Upgrade Microsoft.Identity.Client to 4.60.3 or later

Other vulnerabilities in Microsoft.Identity.Client