CVE-2021-35076
📋 TL;DR
This vulnerability allows attackers to cause denial of service or potentially execute arbitrary code by sending a specially crafted RRC connection reconfiguration message to affected Qualcomm Snapdragon chipsets. It affects devices using Snapdragon Auto, Compute, Connectivity, Industrial IoT, and Mobile platforms.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Industrial IOT
- Snapdragon Mobile
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, data exfiltration, or persistent backdoor installation.
Likely Case
Denial of service causing device crashes, reboots, or loss of cellular connectivity.
If Mitigated
Limited impact with proper network segmentation and intrusion detection systems in place.
🎯 Exploit Status
Exploitation requires sending malformed RRC messages over cellular network; no public exploits available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in public bulletin
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/may-2022-bulletin
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware updates. 2. Apply Qualcomm-provided patches through OEM channels. 3. Reboot device after update.
🔧 Temporary Workarounds
Network segmentation
allIsolate affected devices from untrusted networks
Cellular network filtering
allImplement network-level filtering for suspicious RRC messages
🧯 If You Can't Patch
- Deploy network intrusion detection systems to monitor for abnormal RRC traffic
- Implement strict access controls and network segmentation for affected devices
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against manufacturer's patched versions; no public detection script available.Check Version:
Device-specific commands vary by manufacturer; typically 'adb shell getprop ro.build.version' for Android devices.Verify Fix Applied:
Verify firmware version has been updated to manufacturer's recommended patched version.📡 Detection & Monitoring
Log Indicators:
- Unexpected device reboots
- Baseband processor crashes
- Cellular connectivity loss logs
Network Indicators:
- Abnormal RRC connection reconfiguration messages
- Suspicious cellular network traffic patterns
SIEM Query:
Not applicable - requires specialized cellular network monitoring