CVE-2021-30321
📋 TL;DR
This vulnerability allows remote code execution via buffer overflow in Qualcomm Snapdragon chipsets when processing MBSSID scan information elements. Attackers can exploit this to execute arbitrary code with kernel privileges on affected devices. This affects devices using vulnerable Snapdragon Compute, Connectivity, and Consumer Electronics Connectivity chipsets.
💻 Affected Systems
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Consumer Electronics Connectivity
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code with kernel privileges, potentially leading to persistent backdoors, data theft, or device bricking.
Likely Case
Remote code execution leading to privilege escalation, allowing attackers to bypass security controls and gain persistent access to affected systems.
If Mitigated
Denial of service or system instability if exploit attempts are detected and blocked by security controls.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with network attack vector and no authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Qualcomm security bulletin for specific chipset firmware updates
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/november-2021-bulletin
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply Qualcomm-provided firmware patches. 3. Reboot device to activate patches.
🔧 Temporary Workarounds
Disable MBSSID scanning
allDisable multi-BSSID scanning functionality if supported by device configuration
Device-specific commands vary by manufacturer
Network segmentation
allIsolate affected devices from untrusted networks
🧯 If You Can't Patch
- Isolate affected devices in separate network segments with strict access controls
- Implement network monitoring for abnormal MBSSID scan traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check device chipset version and firmware against Qualcomm advisory. Use 'cat /proc/cpuinfo' on Linux/Android to identify chipset.Check Version:
Device-specific: Check Settings > About Phone on Android or manufacturer firmware toolsVerify Fix Applied:
Verify firmware version has been updated to patched version specified in Qualcomm advisory.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Unexpected process crashes
- Memory corruption warnings in system logs
Network Indicators:
- Abnormal MBSSID scan traffic patterns
- Unexpected network packets targeting wireless interfaces
SIEM Query:
Search for: kernel panic OR buffer overflow AND (qualcomm OR snapdragon) in system logs