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

Low
localden published GHSA-x674-v45j-fwxw Apr 16, 2024

Package

nuget Microsoft.Identity.Client (NuGet)

Affected versions

>=4.48.0, <4.59.1
>= 4.60.0, <4.60.3

Patched versions

4.59.1
4.60.3

Description

Important

ONLY applications targeting Xamarin Android and .NET Android (MAUI) are impacted. All others can safely dismiss this CVE.

Impact

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.

Patches

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.

Workarounds

We recommend developers update to the latest version of MSAL.NET. If that is not possible, a developer may explicitly mark the MSAL.NET activity non-exported:

<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>

References

Refer to MSAL.NET documentation for latest guidance and best practices on configuring client applications using the library.

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L

CVE ID

CVE-2024-27086

Weaknesses

No CWEs

Credits