CVE-2020-11307
📋 TL;DR
A buffer overflow vulnerability in Qualcomm Snapdragon modem firmware allows attackers to execute arbitrary code or cause denial of service. This affects numerous Snapdragon-based devices across automotive, compute, connectivity, consumer IoT, industrial IoT, and wearables platforms. Attackers can exploit this by sending specially crafted packets to the modem.
💻 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 with kernel/system privileges leading to complete device compromise, data exfiltration, or persistent backdoor installation.
Likely Case
Device crash/reboot (denial of service) or limited code execution in modem context, potentially enabling further attacks.
If Mitigated
No impact if patched; limited to denial of service if exploit attempts are detected and blocked.
🎯 Exploit Status
Exploitation requires sending crafted packets to modem interface; no public exploit code available but buffer overflows in modem firmware are attractive targets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to device manufacturer/OEM updates for specific firmware versions
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. 4. Verify modem firmware version is updated.
🔧 Temporary Workarounds
Network segmentation
allRestrict access to modem interfaces from untrusted networks
Firewall rules
allBlock unnecessary modem protocol traffic at network perimeter
🧯 If You Can't Patch
- Isolate affected devices on segmented networks with strict access controls
- Monitor for unusual modem activity or crash logs indicating exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check device manufacturer security bulletins for affected models; examine modem firmware version against patched versions.Check Version:
Device-specific commands vary by OEM; typically through Android settings (Settings > About phone > Baseband version) or modem diagnostic tools.Verify Fix Applied:
Confirm modem firmware has been updated to version containing Qualcomm's July 2021 security patches.📡 Detection & Monitoring
Log Indicators:
- Modem crash logs
- Unexpected modem resets
- Kernel panic messages related to modem
Network Indicators:
- Unusual modem protocol traffic patterns
- Malformed packets to modem ports
SIEM Query:
Search for modem crash events or baseband exceptions in device logs