Multiple critical vulnerabilities have been identified in the TP-Link VN020 F3v(T) router running firmware version TT_V6.2.1021, exposing devices to remote denial-of-service (DoS) and potential remote code execution (RCE) attacks. The flaws, documented in three CVEs, affect UPnP, FTP, and DHCP services, requiring immediate attention from network administrators and security teams.
Executive Summary for Security Leaders
The TP-Link VN020 F3v(T) router contains unpatched vulnerabilities that could allow attackers to crash devices or execute arbitrary code without authentication. These issues stem from improper input validation in core services and affect routers distributed primarily in North African telecom networks. No vendor patches are available as of April 2025, leaving mitigation as the only defensive option.
- CVE-2024-12342: UPnP SOAP request DoS (CVSS 7.5)
- CVE-2024-12344: FTP buffer overflow (CVSS 8.8)
- CVE-2024-11237: DHCP packet RCE (CVSS 9.0)
Technical Analysis of Vulnerabilities
The UPnP vulnerability (CVE-2024-12342) allows remote attackers to crash the router by sending malformed SOAP requests to the WANIPConnection service on port 5431. A proof-of-concept using curl demonstrates how oversized XML payloads in the AddPortMapping action trigger the crash:1
curl -X POST "http://[TARGET_IP]:5431/control/WANIPConnection" -H "SOAPAction: urn:schemas-upnp-org:service:WANIPConnection:1#AddPortMapping" -d '<?xml version="1.0"?><s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body><u:AddPortMapping><NewPortMappingDescription>AAAA...</NewPortMappingDescription></u:AddPortMapping></s:Body></s:Envelope>'The FTP server vulnerability (CVE-2024-12344) involves memory corruption through oversized USER commands. Testing shows that payloads exceeding 1100 bytes cause delayed crashes, while 1450-byte payloads trigger immediate failures. Though currently classified as a DoS issue, the buffer overflow’s structure suggests potential RCE development.2
DHCP Packet Exploitation
The most severe vulnerability (CVE-2024-11237) resides in the DHCP server implementation. Attackers can craft malicious DISCOVER packets containing oversized hostname or vendor-specific options, leading to stack-based buffer overflow. This affects routers deployed by Tunisie Telecom and Topnet ISPs, with Algerian and Moroccan variants also vulnerable. A GitHub repository contains functional PoC code demonstrating the crash condition.3
Mitigation Strategies
Until TP-Link releases firmware updates, organizations should implement these defensive measures:
| Service | Action | Impact |
|---|---|---|
| UPnP | Disable in router settings | Blocks CVE-2024-12342 |
| FTP | Disable if unused or restrict access | Mitigates CVE-2024-12344 |
| DHCP | Use external DHCP server | Prevents CVE-2024-11237 |
Network monitoring for malformed SOAP requests, FTP USER commands exceeding 1000 bytes, and abnormal DHCP traffic can help detect exploitation attempts. Firewall rules should restrict access to ports 5431 (UPnP), 21 (FTP), and 67/68 (DHCP) from untrusted networks.
Conclusion
These TP-Link vulnerabilities demonstrate how protocol implementations in consumer-grade networking equipment can create enterprise-scale risks. The lack of vendor patches emphasizes the need for proactive network segmentation and service hardening. Security teams should inventory affected devices and monitor TP-Link’s security advisories for updates.
References
- “Exploit Database Entry #52250,” Exploit-DB, 2024. [Online]. Available: https://www.exploit-db.com/exploits/52250
- “Exploit Database Entry #52249,” Exploit-DB, 2024. [Online]. Available: https://www.exploit-db.com/exploits/52249
- “TP-Thumper PoC,” GitHub, 2024. [Online]. Available: https://github.com/Zephkek/TP-Thumper
- “NVD Entry for CVE-2024-12342,” NIST, 2024. [Online]. Available: https://nvd.nist.gov/vuln/detail/CVE-2024-12342
- “TP-Link DHCP Vulnerability Analysis,” GBHackers, 2024. [Online]. Available: https://gbhackers.com/tp-link-dhcp-vulnerability/
