CVE-2021-26461
📋 TL;DR
CVE-2021-26461 is an integer overflow vulnerability in Apache NuttX memory allocation functions that allows attackers to trigger arbitrary memory allocation. This can lead to system crashes or remote code execution. Users of Apache NuttX versions before 10.1.0 are affected.
💻 Affected Systems
- Apache NuttX
📦 What is this software?
Nuttx by Apache
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise and attacker persistence
Likely Case
System crashes, denial of service, and potential memory corruption leading to unstable operation
If Mitigated
Controlled crashes without code execution if memory protections are enabled
🎯 Exploit Status
Exploitation requires triggering specific memory allocation patterns but no authentication
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.0 and later
Vendor Advisory: https://lists.apache.org/thread.html/r806fccf8b003ae812d807c6c7d97950d44ed29b2713418cbe3f2bddd%40%3Cdev.nuttx.apache.org%3E
Restart Required: Yes
Instructions:
1. Download Apache NuttX version 10.1.0 or later from official sources. 2. Replace existing installation with patched version. 3. Rebuild and redeploy affected systems. 4. Restart all services using NuttX.
🔧 Temporary Workarounds
Memory allocation limits
allImplement strict memory allocation limits and bounds checking in application code
🧯 If You Can't Patch
- Isolate affected systems in network segments with strict access controls
- Implement application-level input validation and memory usage monitoring
🔍 How to Verify
Check if Vulnerable:
Check NuttX version: if version < 10.1.0, system is vulnerableCheck Version:
Check NuttX build configuration or version header files for version informationVerify Fix Applied:
Verify NuttX version is 10.1.0 or later and check for proper memory allocation behavior📡 Detection & Monitoring
Log Indicators:
- Memory allocation failures
- System crashes
- Unexpected process termination
Network Indicators:
- Unusual memory allocation patterns from network services
SIEM Query:
Search for: (event_type="crash" OR event_type="memory_error") AND process_name="nuttx*"