CVE-2024-21382 Overview
CVE-2024-21382 is an information disclosure vulnerability affecting Microsoft Edge (Chromium-based) for Android. Microsoft identified the issue as an improper permissive cross-domain policy weakness [CWE-942], allowing a remote attacker to expose limited confidential information from the browser to an unauthorized actor. Successful exploitation requires user interaction, such as convincing a target to visit a crafted web page. The vulnerability does not affect the integrity or availability of the mobile browser, only confidentiality.
Critical Impact
A network-based attacker who convinces a mobile user to load a malicious page can obtain limited confidential information from Microsoft Edge for Android through an overly permissive cross-domain policy.
Affected Products
- Microsoft Edge (Chromium-based) for Android
- Google Android platform hosting the affected browser
- Deployments relying on Microsoft Edge as the default mobile browser
Discovery Timeline
- 2024-01-26 - CVE-2024-21382 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2024-21382
Vulnerability Analysis
The vulnerability resides in how Microsoft Edge for Android handles cross-domain policy enforcement. The Common Weakness Enumeration classification [CWE-942] identifies this as a Permissive Cross-domain Policy with Untrusted Domains. Under this weakness, the browser accepts requests or resource loads from domains that should be treated as untrusted. Attackers can leverage this behavior to read data belonging to another origin.
Exploitation is network-based and requires the target to interact with attacker-controlled content. A user must click a link or load a crafted page within the vulnerable browser. Once triggered, the attacker gains read access to a limited scope of confidential information. The flaw does not enable code execution or tampering with browser state.
Root Cause
The root cause is improper enforcement of cross-origin boundaries within the mobile browser. When cross-domain policies grant access more broadly than the Same-Origin Policy allows, a page hosted on one domain can read protected resources from another. Microsoft's advisory does not disclose which subsystem or policy file drives the incorrect trust decision.
Attack Vector
The attack vector is remote over the network with low complexity and no privileges required. The attacker hosts a malicious web page and induces a mobile user running Microsoft Edge for Android to visit it. On visit, the page invokes a cross-origin request that the browser permits under the flawed policy. The response data is then returned to attacker-controlled JavaScript for exfiltration.
No verified proof-of-concept has been published, and Microsoft does not report exploitation in the wild. Consult the Microsoft Security Update CVE-2024-21382 advisory for the vendor's technical guidance.
// No verified public exploit code is available for CVE-2024-21382.
// Refer to the Microsoft Security Response Center advisory for details.
Detection Methods for CVE-2024-21382
Indicators of Compromise
- Unusual outbound HTTP requests from Microsoft Edge for Android to unfamiliar domains immediately after visiting a new URL.
- Cross-origin resource loads in mobile web traffic that reference sensitive first-party endpoints from unrelated third-party origins.
- User reports of unexpected redirects or embedded content on trusted mobile sites.
Detection Strategies
- Inspect mobile proxy or gateway logs for cross-origin fetch and XHR patterns that read authenticated first-party resources.
- Correlate browser telemetry with URL reputation feeds to flag Android sessions that reach known malicious infrastructure.
- Compare installed Microsoft Edge for Android versions against the vendor-patched release to identify vulnerable devices.
Monitoring Recommendations
- Enable mobile device management (MDM) reporting for browser version compliance on all Android endpoints.
- Forward mobile web gateway logs to a central analytics platform to review anomalous cross-domain activity.
- Track user-agent strings identifying Microsoft Edge for Android against expected corporate baselines.
How to Mitigate CVE-2024-21382
Immediate Actions Required
- Update Microsoft Edge for Android to the latest version available in the Google Play Store.
- Enforce automatic updates for managed Android devices through MDM policies.
- Advise users to avoid opening links from untrusted sources on mobile devices until patching is confirmed.
Patch Information
Microsoft issued a fix as part of its security update process. Refer to the Microsoft Security Update CVE-2024-21382 advisory for the specific patched build number and rollout details. Confirm patch deployment by verifying the installed version of Microsoft Edge on each Android device.
Workarounds
- Restrict use of Microsoft Edge for Android on managed devices until the patched version is installed.
- Route mobile browser traffic through a filtering proxy that blocks known malicious domains and enforces safe browsing categories.
- Educate users on the risks of tapping unsolicited links, particularly within messaging and email applications on Android.
# Verify the installed Microsoft Edge version on a managed Android device via ADB
adb shell dumpsys package com.microsoft.emmx | grep versionName
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
