CVE-2021-35096
📋 TL;DR
This vulnerability in Qualcomm Snapdragon chipsets involves improper memory allocation during counter check DLM handling, which can cause denial of service. It affects devices using Snapdragon Auto, Compute, Connectivity, Industrial IoT, and Mobile platforms. Attackers could crash affected systems by triggering this memory allocation flaw.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Industrial IOT
- Snapdragon Mobile
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash or reboot leading to sustained denial of service, potentially affecting critical operations in automotive, industrial, or mobile systems.
Likely Case
System instability, application crashes, or temporary denial of service requiring device restart.
If Mitigated
Minimal impact with proper patching and system monitoring in place.
🎯 Exploit Status
Exploitation requires triggering the vulnerable DLM handling function, which may require specific conditions or malicious application execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates as specified in Qualcomm May 2022 security bulletin
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/may-2022-bulletin
Restart Required: Yes
Instructions:
1. Check with device manufacturer for firmware updates. 2. Apply Qualcomm-provided patches through official firmware updates. 3. Reboot device after update installation.
🔧 Temporary Workarounds
Restrict application permissions
allLimit which applications can access system-level functions that might trigger the vulnerable DLM handling
Monitor system stability
allImplement monitoring for system crashes or abnormal reboots that could indicate exploitation attempts
🧯 If You Can't Patch
- Isolate affected devices from untrusted networks
- Implement strict application whitelisting and monitoring
🔍 How to Verify
Check if Vulnerable:
Check device chipset model and firmware version against Qualcomm's affected list in the May 2022 bulletinCheck Version:
Device-specific commands vary by manufacturer (e.g., 'getprop ro.build.fingerprint' on Android)Verify Fix Applied:
Verify firmware version has been updated to a version after the patch release date (May 2022)📡 Detection & Monitoring
Log Indicators:
- System crash logs
- Kernel panic messages
- Abnormal DLM-related errors
Network Indicators:
- Unusual patterns of device reboots across multiple systems
SIEM Query:
Device logs containing 'kernel panic', 'system crash', or 'DLM error' from Snapdragon-based devices