CVE-2021-0481
📋 TL;DR
This Android vulnerability allows local privilege escalation through unauthorized file access when a user interacts with a malicious app. It affects Android devices running versions 8.1 through 11. The flaw enables attackers to access sensitive files without requiring additional execution privileges.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to access sensitive user data, install persistent malware, or gain system-level privileges.
Likely Case
Local data theft including access to photos, documents, or other user files stored on the device.
If Mitigated
Limited impact with proper app sandboxing and user awareness preventing malicious app installation.
🎯 Exploit Status
Exploitation requires user interaction with a malicious app. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin May 2021 patches
Vendor Advisory: https://source.android.com/security/bulletin/2021-05-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install the May 2021 security patch or later. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable unknown sources
androidPrevent installation of apps from unknown sources to block malicious apps
Settings > Security > Unknown sources (disable)
App permission review
androidReview and restrict app permissions, especially file access permissions
Settings > Apps > [App Name] > Permissions
🧯 If You Can't Patch
- Restrict installation of apps from unknown sources
- Use mobile device management (MDM) to enforce security policies
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If version is 8.1, 9, 10, or 11 without May 2021 security patch, device is vulnerable.Check Version:
Settings > About phone > Android versionVerify Fix Applied:
Verify Android version has May 2021 security patch level in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns from apps
- Permission escalation attempts in system logs
Network Indicators:
- No network indicators - local vulnerability only
SIEM Query:
Not applicable - local device vulnerability