CVE-2021-1905
📋 TL;DR
CVE-2021-1905 is a use-after-free vulnerability in Qualcomm Snapdragon chipsets that allows attackers to potentially execute arbitrary code or cause denial of service. The vulnerability affects multiple Qualcomm product lines including automotive, mobile, IoT, and wearables. Attackers could exploit this to gain elevated privileges on affected devices.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Consumer IOT
- Snapdragon Industrial IOT
- Snapdragon Mobile
- Snapdragon Voice & Music
- Snapdragon Wearables
📦 What is this software?
Sd8c Firmware by Qualcomm
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing remote code execution with kernel privileges, leading to data theft, persistent backdoors, or device bricking.
Likely Case
Local privilege escalation allowing attackers to gain elevated system permissions on compromised devices.
If Mitigated
Limited impact with proper patching and security controls, potentially only denial of service if exploitation fails.
🎯 Exploit Status
Requires local access to exploit. Likely used in targeted attacks given the high value of Snapdragon-based devices.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Varies by device manufacturer - check specific device security updates
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/may-2021-bulletin
Restart Required: Yes
Instructions:
1. Check with device manufacturer for security updates. 2. Apply latest firmware/security patches. 3. Reboot device after patching. 4. Verify patch installation through system settings.
🔧 Temporary Workarounds
Restrict local access
allLimit physical and network access to vulnerable devices to reduce attack surface
Enable security features
linuxEnsure device security features like SELinux, verified boot, and app sandboxing are enabled
🧯 If You Can't Patch
- Isolate affected devices on segmented networks with strict access controls
- Implement application allowlisting and monitor for suspicious process behavior
🔍 How to Verify
Check if Vulnerable:
Check device chipset information and compare with Qualcomm advisory. On Android: Settings > About phone > Hardware infoCheck Version:
Android: adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Check security patch level in device settings and verify it includes May 2021 or later Qualcomm security updates📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Memory corruption errors in dmesg
- Unexpected process privilege escalation
Network Indicators:
- Unusual outbound connections from system processes
- Suspicious local network scanning
SIEM Query:
Process creation events showing unexpected privilege escalation or kernel module loading