CVE-2025-53888
📋 TL;DR
RIOT-OS versions up to 2025.04 have a buffer overflow vulnerability in the l2filter_add() function where assertions are used for input validation instead of proper checks. When assertions are disabled in production builds, attackers can trigger buffer overflows leading to denial of service or arbitrary code execution. This affects IoT devices running vulnerable RIOT-OS versions.
💻 Affected Systems
- RIOT-OS
📦 What is this software?
Riot by Riot Os
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary code execution leading to complete device compromise, lateral movement within IoT networks, and persistent backdoor installation.
Likely Case
Denial of service through device crashes or instability, potentially disrupting IoT network operations.
If Mitigated
No impact if assertions remain enabled or proper input validation is implemented.
🎯 Exploit Status
Exploitation requires sending specially crafted network packets to trigger the buffer overflow condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit f6f7de4ccc107c018630e4c15500825caf02e1c2
Vendor Advisory: https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-7972-w7f9-3j9m
Restart Required: Yes
Instructions:
1. Update RIOT-OS to version after commit f6f7de4ccc107c018630e4c15500825caf02e1c2
2. Rebuild and redeploy firmware
3. Restart affected IoT devices
🔧 Temporary Workarounds
Enable assertions in production
allCompile RIOT-OS with assertions enabled to maintain the size check, though this is not recommended for production.
Build with -DNDEBUG not set or explicitly enable assertions
Network filtering
allImplement network filtering to block malicious packets targeting the l2filter functionality.
🧯 If You Can't Patch
- Segment IoT devices on isolated networks to limit attack surface
- Implement strict network monitoring for abnormal packet patterns targeting l2filter functions
🔍 How to Verify
Check if Vulnerable:
Check RIOT-OS version and examine if l2filter_add() function uses assertions for addr_len validation instead of proper bounds checking.Check Version:
Check RIOT-OS version in build configuration or device firmware informationVerify Fix Applied:
Verify the code contains proper bounds checking for addr_len in l2filter_add() function instead of assertions.📡 Detection & Monitoring
Log Indicators:
- Device crashes or restarts
- Memory corruption errors in system logs
- Abnormal network traffic patterns
Network Indicators:
- Unusual packets targeting l2filter functionality
- Traffic with abnormally large addr_len values
SIEM Query:
Search for: device_type:"RIOT-OS" AND (event:"crash" OR event:"buffer_overflow" OR network.packet_size:>CONFIG_L2FILTER_ADDR_MAXLEN)