CVE-2021-1953
📋 TL;DR
This vulnerability in Qualcomm Snapdragon chipsets allows remote attackers to trigger a reachable assertion by sending malformed Fine Timing Measurement Request (FTMR) frames. Exploitation could lead to denial of service or potentially arbitrary code execution on affected devices. It impacts a wide range of Snapdragon-based products across automotive, mobile, IoT, and networking segments.
💻 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 leading to complete device compromise, potentially allowing attacker to execute arbitrary code with system privileges.
Likely Case
Denial of service causing device crashes or instability, disrupting wireless functionality and connectivity.
If Mitigated
Limited impact with proper network segmentation and access controls preventing malicious FTMR frames from reaching vulnerable devices.
🎯 Exploit Status
Exploitation requires sending specially crafted FTMR frames to vulnerable devices; attacker needs to be within wireless range or have network access
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check device manufacturer for specific 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 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 reception of malicious FTMR frames
Network segmentation
allIsolate vulnerable devices on separate network segments with strict access controls
🧯 If You Can't Patch
- Implement strict network access controls to limit who can send FTMR frames to vulnerable devices
- Deploy network monitoring to detect and block malformed FTMR frames
🔍 How to Verify
Check if Vulnerable:
Check device chipset model and firmware version against Qualcomm's advisory; devices with affected Snapdragon chipsets are vulnerableCheck Version:
Device-specific commands vary by manufacturer; typically 'adb shell getprop ro.build.fingerprint' for Android or manufacturer-specific firmware check toolsVerify Fix Applied:
Verify firmware version has been updated to a version after the patch release date (July 2021 or later)📡 Detection & Monitoring
Log Indicators:
- Unexpected device reboots
- Wi-Fi stack crashes
- Kernel panic logs related to wireless drivers
Network Indicators:
- Unusual FTMR frame patterns
- Malformed 802.11 management frames targeting vulnerable devices
SIEM Query:
Wireless logs showing FTMR frame anomalies OR device crash logs with wireless stack references