CVE-2021-35075
📋 TL;DR
This vulnerability allows attackers to cause denial of service or potentially execute arbitrary code by exploiting a null pointer dereference in Qualcomm Snapdragon WDOG driver registration. It affects devices using Snapdragon Auto, Connectivity, Industrial IoT, and Mobile platforms.
💻 Affected Systems
- Snapdragon Auto
- 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
Device crash or reboot causing denial of service, potentially disrupting critical operations in automotive or industrial systems.
If Mitigated
Limited impact with proper memory protection mechanisms and exploit mitigations in place.
🎯 Exploit Status
Exploitation requires kernel-level access or ability to trigger specific driver operations. No public exploits known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Qualcomm February 2022 security bulletin for specific chipset patches
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/february-2022-bulletin
Restart Required: Yes
Instructions:
1. Check Qualcomm bulletin for affected chipset versions. 2. Contact device manufacturer for firmware updates. 3. Apply provided patches. 4. Reboot device.
🔧 Temporary Workarounds
Disable vulnerable WDOG functionality
linuxIf WDOG features are not required, disable them to prevent exploitation.
echo 0 > /sys/module/wdog_module/parameters/enable
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized kernel access
- Deploy runtime memory protection solutions like ASLR and stack canaries
🔍 How to Verify
Check if Vulnerable:
Check device chipset version and compare against Qualcomm's affected list. Review kernel logs for WDOG-related crashes.Check Version:
cat /proc/cpuinfo | grep -i qualcommVerify Fix Applied:
Verify firmware version has been updated to post-February 2022 patches. Test WDOG functionality stability.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- WDOG driver crash logs
- Null pointer dereference errors in dmesg
Network Indicators:
- Unexpected device reboots
- Service disruptions in industrial/automotive systems
SIEM Query:
source="kernel" AND ("WDOG" OR "null pointer" OR "kernel panic")