CVE-2020-11255
📋 TL;DR
This vulnerability is a memory leak in Qualcomm Snapdragon chipsets when processing RTCP packets with multiple SDES reports. It allows attackers to cause denial of service by exhausting system memory, affecting millions of devices across automotive, mobile, IoT, and wearable platforms.
💻 Affected Systems
- Snapdragon Auto
- Snapdragon Compute
- Snapdragon Connectivity
- Snapdragon Consumer IOT
- Snapdragon Industrial IOT
- Snapdragon IoT
- Snapdragon Mobile
- Snapdragon Wearables
📦 What is this software?
Sd8c Firmware by Qualcomm
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash or device reboot due to memory exhaustion, potentially disrupting critical functions in automotive or industrial systems.
Likely Case
Device instability, application crashes, or degraded performance as memory becomes exhausted over time.
If Mitigated
Minimal impact if patched or if network controls prevent malicious RTCP traffic.
🎯 Exploit Status
Exploitation requires sending specially crafted RTCP packets to vulnerable devices, which may require network access and knowledge of target's RTCP implementation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches included in Qualcomm's April 2021 security bulletin
Vendor Advisory: https://www.qualcomm.com/company/product-security/bulletins/april-2021-bulletin
Restart Required: Yes
Instructions:
1. Check with device manufacturer for firmware updates. 2. Apply Qualcomm-provided patches through OEM updates. 3. Reboot device after update installation.
🔧 Temporary Workarounds
Network filtering
allBlock or filter RTCP traffic at network boundaries
Disable RTCP if not needed
allDisable RTCP functionality in applications/services if not required
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable devices
- Monitor for abnormal memory usage patterns indicating potential exploitation
🔍 How to Verify
Check if Vulnerable:
Check device chipset model and firmware version against Qualcomm's advisory. Use 'getprop ro.boot.hardware' on Android devices to check chipset.Check Version:
On Android: 'getprop ro.build.version.security_patch' and 'getprop ro.boot.hardware'Verify Fix Applied:
Verify firmware version has been updated to post-April 2021 patches from device manufacturer.📡 Detection & Monitoring
Log Indicators:
- Abnormal memory usage patterns
- Application crashes related to RTCP processing
- Kernel OOM (Out of Memory) events
Network Indicators:
- Unusual RTCP traffic patterns
- Multiple SDES reports in RTCP packets
SIEM Query:
Search for memory exhaustion events or process crashes on devices with Snapdragon chipsets