CVE-2021-30303
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code or cause denial of service on affected Qualcomm Snapdragon devices by sending specially crafted segmented WMI commands that trigger a buffer overflow. It affects a wide range of Snapdragon platforms including automotive, mobile, IoT, and networking products. Attackers could potentially gain elevated privileges or crash systems.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Consumer Electronics Connectivity
- Snapdragon Consumer IOT
- Snapdragon Industrial IOT
- Snapdragon Mobile
- Snapdragon Voice & Music
- Snapdragon Wired Infrastructure and Networking
📦 What is this software?
Sd7c Firmware by Qualcomm
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with kernel privileges leading to complete system compromise, data theft, or persistent backdoor installation.
Likely Case
Denial of service causing system crashes or instability, potentially requiring physical reset.
If Mitigated
Limited impact with proper network segmentation and access controls preventing malicious WMI command delivery.
🎯 Exploit Status
Exploitation requires sending malicious segmented WMI commands to the vulnerable component. No public exploit code has been disclosed as of knowledge cutoff.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Qualcomm security bulletin for specific patched versions per product line.
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/december-2021-bulletin
Restart Required: Yes
Instructions:
1. Check Qualcomm security bulletin for your specific product. 2. Obtain firmware/driver updates from device manufacturer (OEM). 3. Apply updates following OEM instructions. 4. Reboot device to activate patched firmware.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict network access to WMI interfaces to prevent unauthorized command delivery.
iptables -A INPUT -p tcp --dport [WMI_PORT] -j DROP
iptables -A INPUT -p udp --dport [WMI_PORT] -j DROP
Disable WMI if Unused
linuxDisable WMI functionality if not required for device operation.
echo 0 > /sys/module/wmi/parameters/enabled
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable devices from untrusted networks.
- Deploy intrusion detection systems to monitor for anomalous WMI command patterns.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against Qualcomm security bulletin. Use 'cat /proc/version' or OEM-specific commands to identify chipset and firmware.Check Version:
cat /proc/version | grep -i qualcomm || cat /sys/firmware/devicetree/base/modelVerify Fix Applied:
Verify firmware version has been updated to patched version listed in Qualcomm bulletin. Check with 'dmesg | grep -i wmi' for any error messages after update.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- WMI driver crash messages in dmesg
- Unexpected system reboots
Network Indicators:
- Unusual WMI command traffic patterns
- Multiple segmented WMI packets from single source
SIEM Query:
source="kernel" AND "WMI" AND ("panic" OR "segmentation fault" OR "buffer overflow")