CVE-2021-46381
📋 TL;DR
This CVE describes a path traversal vulnerability in D-Link DAP-1620 devices that allows attackers to read sensitive system files like /etc/passwd and /etc/shadow. Attackers can exploit this to gain unauthorized access to user credentials and system information. Organizations using affected D-Link DAP-1620 devices are vulnerable.
💻 Affected Systems
- D-Link DAP-1620
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise through credential theft from /etc/shadow leading to privilege escalation and complete device takeover.
Likely Case
Unauthorized reading of sensitive system files containing user credentials and configuration data.
If Mitigated
Limited information disclosure if proper network segmentation and access controls prevent exploitation attempts.
🎯 Exploit Status
Public exploit code available on Packet Storm Security. Simple HTTP requests with path traversal payloads.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link security bulletin for latest firmware
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Visit D-Link support site 2. Download latest firmware for DAP-1620 3. Log into device web interface 4. Navigate to firmware update section 5. Upload and apply new firmware 6. Reboot device
🔧 Temporary Workarounds
Network Segmentation
allIsolate DAP-1620 devices from untrusted networks and restrict web interface access
Access Control Lists
allImplement firewall rules to restrict access to device management interface
🧯 If You Can't Patch
- Remove device from internet-facing positions and place behind firewall
- Implement strict network segmentation to limit device access to trusted hosts only
🔍 How to Verify
Check if Vulnerable:
Attempt to access http://device-ip/../../../../etc/passwd via web browser or curlCheck Version:
Check firmware version in device web interface under System > FirmwareVerify Fix Applied:
After patching, same path traversal attempts should return error pages or be blocked📡 Detection & Monitoring
Log Indicators:
- HTTP requests containing '..' sequences
- Access attempts to /etc/passwd or /etc/shadow
Network Indicators:
- Unusual HTTP requests with directory traversal patterns to device IP
SIEM Query:
source="web_logs" AND (uri="*..*" OR uri="*/etc/passwd*" OR uri="*/etc/shadow*")🔗 References
- http://packetstormsecurity.com/files/167070/DLINK-DAP-1620-A1-1.01-Directory-Traversal.html
- https://drive.google.com/drive/folders/19OP09msw8l7CJ622nkvnvnt7EKun1eCG?usp=sharing
- https://www.dlink.com/en/security-bulletin/
- http://packetstormsecurity.com/files/167070/DLINK-DAP-1620-A1-1.01-Directory-Traversal.html
- https://drive.google.com/drive/folders/19OP09msw8l7CJ622nkvnvnt7EKun1eCG?usp=sharing
- https://www.dlink.com/en/security-bulletin/
