CVE-2024-49057: Microsoft Defender Spoofing Vulnerability

CVE-2024-49057 Overview

CVE-2024-49057 is a spoofing vulnerability affecting Microsoft Defender for Endpoint on Android. Microsoft has assigned this issue a CVSS 3.1 base score of 8.1, placing it in the high severity range. The flaw stems from improper input validation [CWE-20] in the mobile endpoint security agent. An unauthenticated attacker over the network can leverage the vulnerability when a user interacts with a crafted request or content. Successful exploitation can lead to high impact on confidentiality and integrity of the affected application. The vulnerability was published to the National Vulnerability Database on December 12, 2024.

Critical Impact
A successful spoof allows an attacker to impersonate trusted Defender for Endpoint content on Android, undermining trust signals and enabling further compromise of confidentiality and integrity.

Affected Products

Microsoft Defender for Endpoint on Android
Mobile deployments of microsoft:defender_for_endpoint distributed through Google Play
Enterprise tenants using Defender for Endpoint as a Mobile Threat Defense agent on Android

Discovery Timeline

2024-12-12 - CVE-2024-49057 published to NVD by Microsoft
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2024-49057

Vulnerability Analysis

The vulnerability resides in the Android build of Microsoft Defender for Endpoint. Microsoft classifies the issue as a spoofing weakness rooted in improper input validation [CWE-20]. An attacker delivers crafted input over the network that the Defender for Endpoint Android client fails to validate adequately. The client then renders or processes attacker-controlled content as if it were legitimate. This breaks the trust boundary between Defender's security UI or telemetry and external network sources.

User interaction is required, meaning the target must take an action such as opening a link, message, or notification associated with the application. The impact on confidentiality and integrity is rated high, while availability is unaffected. Spoofing of a security agent is particularly damaging because users rely on Defender alerts and indicators to make trust decisions about other applications and content.

Root Cause

The root cause is improper input validation within the Defender for Endpoint Android client. The application accepts attacker-influenced data without verifying its source, structure, or authenticity. This allows crafted inputs to manipulate displayed information or downstream processing.

Attack Vector

The attack vector is network based with low complexity and no required privileges. An attacker hosts or transmits crafted content that reaches the Defender for Endpoint Android application. The user must interact with the content, for example by tapping a link or opening a delivered message. Once processed, the application surfaces spoofed content or behavior to the user. No verified public proof-of-concept code is available, and there are no confirmed reports of exploitation in the wild. See the Microsoft Security Update CVE-2024-49057 advisory for vendor-supplied technical details.

Detection Methods for CVE-2024-49057

Indicators of Compromise

Android devices running outdated Microsoft Defender for Endpoint client versions earlier than the patched release referenced in the Microsoft advisory.
Unexpected Defender for Endpoint notifications, alerts, or in-app prompts originating from external links or messaging applications.
Network requests from the Defender for Endpoint app to domains outside Microsoft's published telemetry and update endpoints.

Detection Strategies

Inventory Android endpoints through mobile device management (MDM) and confirm Defender for Endpoint is at the patched version published by Microsoft.
Correlate user-reported anomalous Defender notifications with proxy or DNS logs to identify crafted content delivery.
Monitor Microsoft 365 Defender portal telemetry for inconsistencies between device-reported state and cloud-side posture for Android assets.

Monitoring Recommendations

Enable mobile threat defense telemetry forwarding to a centralized SIEM for cross-correlation with email and web gateway logs.
Track Google Play deployment status for Defender for Endpoint across the Android fleet and alert on devices stuck on vulnerable versions.
Review user-reported phishing and suspicious link submissions for references to Defender-themed lures.

How to Mitigate CVE-2024-49057

Immediate Actions Required

Update Microsoft Defender for Endpoint on Android to the version identified in the Microsoft Security Update CVE-2024-49057 advisory.
Force application updates through Managed Google Play and Intune app configuration policies to remove user-controlled deferral.
Communicate to end users that Defender alerts should be validated within the Microsoft 365 Defender portal rather than acted on from external links.

Patch Information

Microsoft has released an updated version of Defender for Endpoint for Android that addresses the input validation flaw. Patch distribution is handled through Google Play. Administrators should reference the official Microsoft Security Update CVE-2024-49057 advisory for the exact fixed build number and deployment guidance.

Workarounds

Restrict user interaction with untrusted links and attachments on Android devices via mobile application protection policies until the patched client is deployed.
Enforce conditional access policies that require a compliant Defender for Endpoint version before granting access to corporate resources.
Increase user awareness training focused on recognizing spoofed security prompts and verifying alerts through trusted administrative channels.

bash

# Configuration example: Intune PowerShell snippet to report Android devices
# running Defender for Endpoint and flag non-compliant versions
Connect-MgGraph -Scopes "DeviceManagementManagedDevices.Read.All"
Get-MgDeviceManagementManagedDevice -Filter "operatingSystem eq 'Android'" |
  Select-Object DeviceName, UserPrincipalName, OsVersion, ComplianceState |
  Export-Csv -Path .\android-defender-inventory.csv -NoTypeInformation