CVE-2021-25387
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code on the mediaextractor process in Samsung devices through improper input validation in the libsflacextractor library. It affects Samsung mobile devices running Android with the vulnerable library prior to the May 2021 security update. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- Samsung mobile devices
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover with root/system privileges, allowing data theft, persistent backdoor installation, and device bricking.
Likely Case
Remote code execution with mediaextractor process privileges, potentially leading to data exfiltration, surveillance, or further privilege escalation.
If Mitigated
Limited impact with proper security updates applied and exploit mitigations enabled.
🎯 Exploit Status
Exploitation requires triggering the vulnerable function with malicious media files, potentially through web browsing or app interactions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: SMR MAY-2021 Release 1 or later
Vendor Advisory: https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=5
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Install May 2021 security update or later. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable automatic media file processing
androidPrevent automatic parsing of media files by untrusted applications
Restrict media file sources
allOnly open media files from trusted sources
🧯 If You Can't Patch
- Isolate affected devices from untrusted networks
- Implement application allowlisting to prevent untrusted apps from processing media files
🔍 How to Verify
Check if Vulnerable:
Check device security patch level in Settings > About phone > Software information. If before May 2021, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows May 2021 or later in device settings.📡 Detection & Monitoring
Log Indicators:
- Mediaextractor process crashes
- Suspicious media file processing attempts
Network Indicators:
- Unusual outbound connections from mediaextractor process
SIEM Query:
process_name:mediaextractor AND (event_type:crash OR suspicious_file_activity)