CVE-2023-35676
📋 TL;DR
This vulnerability allows local privilege escalation on Android devices through an unsafe PendingIntent in the Quick Share functionality. Attackers can trigger background activity launches without user interaction, potentially gaining elevated privileges. All Android devices running vulnerable versions are affected.
💻 Affected Systems
- Android OS
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing installation of malware, data theft, and persistent backdoor access.
Likely Case
Limited privilege escalation allowing access to sensitive app data and system functions.
If Mitigated
No impact if patched; otherwise, risk depends on device security settings and user behavior.
🎯 Exploit Status
Exploitation requires crafting a malicious app or having local access; no user interaction needed once triggered.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin September 2023 patches
Vendor Advisory: https://source.android.com/security/bulletin/2023-09-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install the September 2023 security patch. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable Quick Share
androidTemporarily disable the Quick Share feature to prevent exploitation.
Settings > Connected devices > Connection preferences > Quick Share > Turn off
🧯 If You Can't Patch
- Restrict installation of unknown apps from untrusted sources
- Use mobile device management (MDM) to enforce security policies and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If version is 11, 12, 12L, or 13 without September 2023 patches, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level in Settings > About phone > Android version. Ensure 'Android security update' shows September 5, 2023 or later.📡 Detection & Monitoring
Log Indicators:
- Unusual background activity launches from SaveImageInBackgroundTask
- Suspicious PendingIntent usage in system logs
Network Indicators:
- None - this is a local exploit
SIEM Query:
Not applicable for typical SIEM monitoring as this is a local device vulnerability🔗 References
- https://android.googlesource.com/platform/frameworks/base/+/109e58b62dc9fedcee93983678ef9d4931e72afa
- https://source.android.com/security/bulletin/2023-09-01
- https://android.googlesource.com/platform/frameworks/base/+/109e58b62dc9fedcee93983678ef9d4931e72afa
- https://source.android.com/security/bulletin/2023-09-01
