CVE-2021-1965
📋 TL;DR
CVE-2021-1965 is a critical buffer overflow vulnerability in Qualcomm Snapdragon chipsets affecting multiple product lines. Attackers can exploit this by sending specially crafted MBSSID scan information elements to trigger memory corruption, potentially leading to remote code execution. This affects devices using vulnerable Snapdragon Auto, Compute, Connectivity, Mobile, and Wired Infrastructure chips.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Mobile
- Snapdragon Wired Infrastructure and Networking
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with kernel privileges leading to complete device compromise, data theft, and persistent backdoor installation.
Likely Case
Device crash/reboot (DoS) or limited code execution in Wi-Fi subsystem context, potentially enabling further privilege escalation.
If Mitigated
Denial of service through device crashes if exploit attempts are blocked or fail.
🎯 Exploit Status
Exploitation requires crafting malicious MBSSID scan IE packets and sending them to target device over Wi-Fi. No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Qualcomm security bulletin for specific chipset firmware updates.
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/july-2021-bulletin
Restart Required: Yes
Instructions:
1. Check with device manufacturer for firmware/security updates. 2. Apply Qualcomm-provided patches through OEM update channels. 3. Reboot device after update installation.
🔧 Temporary Workarounds
Disable Wi-Fi when not needed
allTurn off Wi-Fi functionality to prevent exploitation via malicious packets.
# Android: adb shell svc wifi disable
# Linux: sudo nmcli radio wifi off
Network segmentation
allIsolate vulnerable devices on separate network segments with strict firewall rules.
🧯 If You Can't Patch
- Implement strict network access controls to limit Wi-Fi exposure to trusted networks only.
- Deploy network intrusion detection systems to monitor for MBSSID scan IE anomalies.
🔍 How to Verify
Check if Vulnerable:
Check device chipset model and firmware version against Qualcomm's advisory. Use 'cat /proc/cpuinfo' or device settings to identify Snapdragon chipset.Check Version:
# Android: getprop ro.bootloader or check Settings > About phone
# Linux: dmesg | grep -i qualcommVerify Fix Applied:
Verify firmware version has been updated to patched version specified in Qualcomm bulletin. Check with OEM for specific update verification steps.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Wi-Fi driver crash messages
- Unexpected device reboots
Network Indicators:
- Unusual MBSSID scan packets on Wi-Fi networks
- Malformed 802.11 management frames
SIEM Query:
source="wifi_logs" AND ("MBSSID" OR "scan IE" OR "buffer overflow")