CVE-2021-1933
📋 TL;DR
This vulnerability allows remote attackers to trigger a UE (User Equipment) assertion in Qualcomm Snapdragon chipsets by sending a specially crafted SIP INVITE message with an SDP body. Affected devices include automotive, compute, connectivity, consumer IoT, industrial IoT, and wearable products using vulnerable Snapdragon chipsets.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Consumer IOT
- Snapdragon Industrial IOT
- Snapdragon Wearables
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, denial of service, or unauthorized access to device functions.
Likely Case
Device crash or denial of service through assertion failure, potentially requiring reboot.
If Mitigated
No impact if patched or if vulnerable components are not exposed to untrusted networks.
🎯 Exploit Status
Exploitation requires sending malformed SIP messages to vulnerable devices; CVSS 9.8 suggests high severity with network attack vector.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Qualcomm September 2021 security bulletin for specific chipset firmware updates.
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/september-2021-bulletin
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply Qualcomm-provided patches through OEM updates. 3. Reboot device after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate devices from untrusted networks to prevent SIP message attacks.
SIP Firewall Rules
linuxBlock or filter SIP traffic to vulnerable devices if not required.
iptables -A INPUT -p udp --dport 5060 -j DROP
iptables -A INPUT -p tcp --dport 5060 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit SIP traffic to trusted sources only.
- Monitor for abnormal SIP message patterns or device crashes as indicators of exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check device chipset model and firmware version against Qualcomm's advisory; no simple command available.Check Version:
Device-specific; typically 'getprop ro.bootloader' or similar on Android devices, or check OEM system info.Verify Fix Applied:
Verify firmware version has been updated to a patched release per manufacturer documentation.📡 Detection & Monitoring
Log Indicators:
- Device crash logs mentioning UE assertion or SIP processing errors
- Unexpected reboots or service restarts
Network Indicators:
- Unusual SIP INVITE messages with malformed SDP bodies
- SIP traffic from untrusted sources to vulnerable ports
SIEM Query:
Example: 'sip AND (invite OR sdp) AND (malformed OR error)' in network traffic logs.