CVE-2023-6542
📋 TL;DR
This vulnerability in the Emarsys SDK for Android allows attackers to bypass authorization checks and launch arbitrary web pages or deep links from the host application. Attackers can navigate users to malicious URLs or trigger unintended app functionality. This affects Android applications using the vulnerable Emarsys SDK.
💻 Affected Systems
- Emarsys SDK for Android
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could redirect users to phishing sites, steal credentials, trigger malicious deep links to compromise other apps, or perform unauthorized actions within the host application.
Likely Case
Attackers would redirect users to phishing pages or unwanted advertisements, potentially leading to credential theft or malware installation.
If Mitigated
With proper input validation and authorization controls, the attack surface is reduced, but the vulnerability could still be exploited through other vectors.
🎯 Exploit Status
Exploitation requires the attacker to call a specific activity in the SDK, which can be done without authentication. No public proof-of-concept is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in references, but SAP notes indicate fixes are available
Vendor Advisory: https://me.sap.com/notes/3406244
Restart Required: Yes
Instructions:
1. Review SAP note 3406244 for patch details. 2. Update the Emarsys SDK to the latest secure version. 3. Rebuild and redeploy the Android application. 4. Test the application to ensure functionality is preserved.
🔧 Temporary Workarounds
Input Validation and Authorization
allImplement strict input validation and authorization checks before processing URLs or deep links.
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable applications from untrusted networks.
- Use web application firewalls (WAF) to block malicious URL patterns and deep link attempts.
🔍 How to Verify
Check if Vulnerable:
Check the Emarsys SDK version in your Android project's build.gradle or dependencies. Compare with SAP's advisory for vulnerable versions.Check Version:
grep -r 'emarsys' build.gradle or check dependencies in Android StudioVerify Fix Applied:
After updating the SDK, test the application by attempting to trigger deep links or URL navigation from unauthorized contexts to ensure they are blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual deep link or URL navigation events in application logs
- Failed authorization attempts for activity calls
Network Indicators:
- Unexpected outbound HTTP/HTTPS requests to unknown domains from the app
SIEM Query:
source="android_app" AND (event="deep_link_triggered" OR event="url_navigation") AND user="unauthorized"