CVE-2021-25410
📋 TL;DR
This vulnerability in Samsung's CallBGProvider component allows local attackers to bypass access controls and read arbitrary files with elevated privileges. It affects Samsung devices running Android prior to the June 2021 security update. Attackers need local access to the device to exploit this flaw.
💻 Affected Systems
- Samsung Android devices
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Local attackers could access sensitive system files, user data, or credentials stored on the device, potentially leading to complete device compromise.
Likely Case
Local malicious apps or users could access private user data, configuration files, or other sensitive information they shouldn't have permission to read.
If Mitigated
With proper access controls, only authorized system components can access the protected files, preventing unauthorized data exposure.
🎯 Exploit Status
Exploitation requires local access to the device. The vulnerability details and exploitation methods have been publicly documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: SMR JUN-2021 Release 1 or later
Vendor Advisory: https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=6
Restart Required: Yes
Instructions:
1. Check for system updates in device Settings > Software update. 2. Install the June 2021 security update or later. 3. Restart the device after installation completes.
🔧 Temporary Workarounds
Disable unnecessary permissions
androidReview and restrict app permissions, especially for apps that don't need access to system components or files.
🧯 If You Can't Patch
- Restrict physical access to devices and implement strong device management policies
- Monitor for suspicious file access patterns and implement application whitelisting
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Software information. If patch level is earlier than June 2021, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows 'June 1, 2021' or later in Settings > About phone > Software information.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns from non-system apps
- Access attempts to protected system directories
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Look for file access events from non-system processes to sensitive directories like /data, /system, or application-specific protected storage