CVE-2021-0967
📋 TL;DR
This vulnerability allows an attacker to write data beyond allocated memory bounds in Android's Vorbis audio codec library. It could lead to remote information disclosure without requiring additional privileges, though user interaction is needed for exploitation. Affects Android devices running versions 9 through 12.
💻 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
Remote attacker could execute arbitrary code, gain full device control, and access sensitive user data through memory corruption leading to information disclosure.
Likely Case
Information disclosure where attacker can read adjacent memory contents, potentially exposing sensitive data like authentication tokens or personal information.
If Mitigated
With proper security controls like ASLR and sandboxing, impact is limited to information disclosure within the affected app's memory space.
🎯 Exploit Status
Exploitation requires user interaction (such as playing a malicious audio file) and knowledge of memory layout.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin December 2021 patches
Vendor Advisory: https://source.android.com/security/bulletin/2021-12-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > Advanced > System update. 2. Install the December 2021 security patch or later. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable Vorbis audio processing
androidPrevent apps from processing Vorbis audio files to mitigate the vulnerability
Use app sandboxing restrictions
androidRestrict vulnerable apps from accessing sensitive data through Android's app permissions
🧯 If You Can't Patch
- Isolate affected devices from untrusted networks
- Implement application allowlisting to prevent untrusted apps from processing audio files
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If version is 9, 10, 11, or 12 without December 2021 security patches, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android Security Patch Level shows December 2021 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Crash logs from media processing services
- SIGSEGV signals in audio codec processes
Network Indicators:
- Unusual audio file downloads to Android devices
- Suspicious media streaming to vulnerable devices
SIEM Query:
source="android_logs" AND (process="mediaserver" OR process="audioflinger") AND (event="segmentation_fault" OR event="SIGSEGV")