CVE-2023-21029
📋 TL;DR
This vulnerability in Android 13 allows local apps to access app usage data without proper permission checks, potentially exposing which apps are being used and when. It affects Android devices running version 13, requiring local execution privileges but no user interaction for exploitation.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker could monitor app usage patterns to infer sensitive user activities, such as financial or health app usage, leading to privacy breaches or targeted attacks.
Likely Case
Malicious apps could collect app usage statistics for advertising or profiling purposes without user consent, compromising privacy.
If Mitigated
With proper app sandboxing and security updates, the risk is minimized to low, as only local apps with limited privileges can exploit it.
🎯 Exploit Status
Exploitation involves local app code execution; no public proof-of-concept has been disclosed, but the vulnerability is straightforward to exploit given the missing permission check.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android security patch level March 2023 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2023-03-01
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Install the March 2023 Android security patch or later. 3. Restart the device to apply the update.
🔧 Temporary Workarounds
Restrict app installations
androidLimit installation of untrusted apps to reduce the risk of malicious local exploitation.
Enable 'Install unknown apps' restrictions in Android settings for all apps.
🧯 If You Can't Patch
- Monitor device for unusual app behavior and uninstall suspicious apps.
- Use security software to detect and block apps attempting to access sensitive data without permissions.
🔍 How to Verify
Check if Vulnerable:
Check the Android security patch level in Settings > About phone > Android version; if it is before March 2023, the device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify the security patch level is March 2023 or later after applying the update.📡 Detection & Monitoring
Log Indicators:
- Log entries showing unauthorized access to UidObserverController or app usage data without proper permissions.
Network Indicators:
- None, as this is a local vulnerability with no network activity.
SIEM Query:
Search for events related to UidObserverController or permission denials in Android system logs.