CVE-2023-21272
📋 TL;DR
This vulnerability in Android's Uri.java allows improper URI permission grants due to insufficient input validation. It enables local privilege escalation without requiring user interaction or additional execution privileges. All Android devices running vulnerable versions are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains elevated system privileges, potentially accessing sensitive data, modifying system files, or installing persistent malware.
Likely Case
Malicious apps exploit this to bypass sandbox restrictions, access other apps' data, or perform unauthorized system operations.
If Mitigated
With proper patching, the vulnerability is eliminated; with app sandboxing and minimal permissions, impact is limited even if exploited.
🎯 Exploit Status
Exploitation requires crafting malicious URIs but doesn't need user interaction; local access or malicious app installation is needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: August 2023 Android Security Patch or later
Vendor Advisory: https://source.android.com/security/bulletin/2023-08-01
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > System update. 2. Install the August 2023 or later security patch. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Restrict app installations
androidOnly install apps from trusted sources like Google Play Store to reduce risk of malicious apps exploiting this vulnerability.
Minimize app permissions
androidReview and restrict unnecessary permissions for installed apps to limit potential damage if exploited.
🧯 If You Can't Patch
- Isolate vulnerable devices from critical networks and sensitive data
- Implement application allowlisting to prevent unauthorized app installations
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version > Security patch level. If before August 2023, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows August 2023 or later date after applying update.📡 Detection & Monitoring
Log Indicators:
- Unusual permission grants in system logs
- Suspicious URI parsing activities
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Not applicable for typical SIEM monitoring of this local Android vulnerability🔗 References
- https://android.googlesource.com/platform/frameworks/base/+/4dea696369a309cf39daa3e94fec7156c290a9c2
- https://source.android.com/security/bulletin/2023-08-01
- https://android.googlesource.com/platform/frameworks/base/+/4dea696369a309cf39daa3e94fec7156c290a9c2
- https://source.android.com/security/bulletin/2023-08-01
