CVE-2025-13735
📋 TL;DR
An out-of-bounds read vulnerability in ASR Lapwing_Linux affects ASR1903 and ASR3901 devices running the nr_fw module. This allows attackers to read memory beyond allocated buffers, potentially exposing sensitive information or causing crashes. Systems running Lapwing_Linux before November 26, 2025 are vulnerable.
💻 Affected Systems
- ASR1903
- ASR3901
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Information disclosure of sensitive kernel or process memory, potential denial of service through system crashes, or possible remote code execution if combined with other vulnerabilities.
Likely Case
Information disclosure leading to exposure of sensitive data or denial of service through application crashes.
If Mitigated
Limited impact with proper network segmentation and access controls, potentially only affecting availability of specific services.
🎯 Exploit Status
Out-of-bounds read vulnerabilities typically require specific conditions to exploit effectively. No public exploit code has been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Lapwing_Linux version dated 2025/11/26 or later
Vendor Advisory: https://www.asrmicro.com/en/goods/psirt?cid=41
Restart Required: Yes
Instructions:
1. Download latest firmware from ASR vendor portal. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Reboot device. 5. Verify update was successful.
🔧 Temporary Workarounds
Disable nr_fw module
linuxTemporarily disable the vulnerable nr_fw module if not required for operation
modprobe -r nr_fw
Network segmentation
allIsolate affected devices from untrusted networks
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Monitor systems for abnormal behavior or crashes
🔍 How to Verify
Check if Vulnerable:
Check Lapwing_Linux version date: cat /etc/lapwing_version or check firmware version in device management interfaceCheck Version:
cat /etc/lapwing_version || grep -i version /proc/versionVerify Fix Applied:
Verify version shows 2025/11/26 or later date, and test nr_fw module functionality📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- nr_fw module crash logs
- Memory access violation errors
Network Indicators:
- Unusual traffic patterns to/from affected devices
- Service disruption on affected ports
SIEM Query:
source="*kernel*" AND ("panic" OR "oops" OR "segfault") AND ("nr_fw" OR "ASR")