CVE-2021-30326
📋 TL;DR
This vulnerability in Qualcomm Snapdragon chipsets allows remote attackers to cause denial of service through improper size validation of DownlinkPreemption IE in RRC messages. It affects Snapdragon Auto, Compute, Connectivity, Industrial IoT, and Mobile platforms. Attackers can trigger assertion failures leading to device crashes.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Industrial IOT
- Snapdragon Mobile
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote denial of service causing device crashes and service disruption across affected platforms, potentially affecting critical systems in automotive, industrial, and mobile environments.
Likely Case
Service disruption through device crashes requiring reboots, impacting connectivity and functionality of affected devices.
If Mitigated
Minimal impact with proper network segmentation and updated firmware preventing exploitation attempts.
🎯 Exploit Status
Exploitation requires sending specially crafted RRC messages to the cellular/baseband interface. No authentication needed but requires network access to the vulnerable interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates as specified in Qualcomm February 2022 bulletin
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/february-2022-bulletin
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply Qualcomm-provided firmware patches. 3. Reboot affected devices. 4. Verify firmware version matches patched release.
🔧 Temporary Workarounds
Network Segmentation
allIsolate cellular/baseband interfaces from untrusted networks
Access Control
allRestrict network access to cellular/baseband interfaces
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected devices
- Monitor for abnormal RRC message patterns and device crashes
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against Qualcomm advisory. Use manufacturer-specific tools to query baseband firmware version.Check Version:
Manufacturer-specific commands vary by device. Typically AT commands or device management interfaces.Verify Fix Applied:
Verify firmware version matches patched release from manufacturer. Monitor for RRC-related crashes after patch application.📡 Detection & Monitoring
Log Indicators:
- Baseband assertion failures
- RRC processing errors
- Unexpected device reboots
- Cellular interface crashes
Network Indicators:
- Malformed RRC messages
- Abnormal RRC Reconfiguration/Setup patterns
- Suspicious cellular traffic
SIEM Query:
Search for baseband crash logs, RRC protocol anomalies, or device reboot events in affected platforms