A critical stack-based buffer overflow vulnerability (CVE-2025-4007) has been identified in Tenda W12 and i24 routers, affecting firmware versions 3.0.0.4(2887) and 3.0.0.5(3644). The flaw resides in the HTTPd module’s `cgidhcpsCfgSet` function, which mishandles the `json` argument, allowing remote attackers to execute arbitrary code. With a CVSSv3 score of 8.8 (High), this vulnerability poses significant risks to network security, especially since a public proof-of-concept (PoC) exploit is already available1.
Technical Details of CVE-2025-4007
The vulnerability stems from improper bounds checking in the `cgidhcpsCfgSet` function within the `/goform/modules` component of the router’s HTTPd service. When processing maliciously crafted JSON input, the function fails to validate the length of the input data, leading to a stack-based buffer overflow2. This flaw can be exploited remotely without authentication, making it particularly dangerous for exposed devices. According to VulDB, the exploit was disclosed on April 26, 2025, and a PoC was released the same day3.
The HTTPd service in Tenda routers is responsible for handling administrative requests, including DHCP configuration changes. Attackers can trigger the vulnerability by sending a specially crafted HTTP POST request to the affected endpoint. Successful exploitation could allow full control over the router, enabling further network compromise. The GitHub Advisory page confirms the availability of exploit code, highlighting the ease of exploitation4.
Affected Products and Firmware Versions
The vulnerability impacts two Tenda router models: W12 and i24. The affected firmware versions are 3.0.0.4(2887) and 3.0.0.5(3644). These devices are commonly used in small office and home office (SOHO) environments, making them attractive targets for attackers seeking to infiltrate networks. Tenable’s analysis confirms the critical rating and remote attack vector, noting that the vulnerability was updated in their database 12 hours ago5.
Tenda has not yet released patches for this vulnerability as of April 28, 2025. This lack of immediate remediation increases the risk for users of these devices. The absence of mitigations, as noted by VulDB, suggests that replacing affected hardware may be the only viable solution for some organizations3.
Mitigation and Remediation Steps
Given the severity of CVE-2025-4007 and the absence of patches, users of affected Tenda routers should take immediate action to reduce risk. The following steps are recommended:
– Disable remote management features on the router to limit exposure to external attacks.
– Monitor network traffic for unusual activity, particularly HTTP POST requests to `/goform/modules`.
– Consider replacing affected routers with models from vendors that provide timely security updates.
For organizations unable to replace hardware immediately, network segmentation can help contain potential breaches. Isolating affected routers from critical internal networks may prevent lateral movement by attackers. Additionally, implementing strict firewall rules to block unauthorized access to the router’s administrative interface can reduce the attack surface.
Relevance to Security Professionals
This vulnerability is particularly relevant for those responsible for network security. The availability of a public PoC increases the likelihood of widespread exploitation, requiring prompt action. Security teams should prioritize identifying affected devices within their networks and applying the recommended mitigations. The flaw also serves as a reminder of the risks associated with using consumer-grade networking equipment in enterprise environments, where timely patching is often challenging.
The vulnerability’s remote exploitability and high CVSS score make it a prime candidate for inclusion in penetration testing scenarios. Red teams may use this flaw to demonstrate the potential impact of unpatched devices in a network. Blue teams, on the other hand, should focus on detection and response strategies, such as logging and analyzing HTTP requests to router administrative interfaces.
Conclusion
CVE-2025-4007 represents a significant threat to networks using vulnerable Tenda routers. The combination of remote exploitability, public PoC availability, and lack of vendor patches creates a perfect storm for potential attacks. Organizations must act quickly to mitigate risks, either by applying workarounds or replacing affected devices entirely. This incident underscores the importance of maintaining up-to-date firmware and choosing networking equipment from vendors with strong security track records.
References
- “CVE-2025-4007 Detail,” National Vulnerability Database, Apr. 2025. [Online]. Available: https://nvd.nist.gov/vuln/detail/CVE-2025-4007
- “Tenda W12 and i24 HTTPd Stack-Based Buffer Overflow,” Tenable, Apr. 2025. [Online]. Available: https://www.tenable.com/cve/CVE-2025-4007
- “Vulnerability DB ID 306343: Tenda Router HTTPd Overflow,” VulDB, Apr. 2025. [Online]. Available: https://vuldb.com/?id.306343
- “GHSA-rxjp-vx38-m3vx: Tenda Router Exploit,” GitHub Advisory Database, Apr. 2025. [Online]. Available: https://github.com/advisories/GHSA-rxjp-vx38-m3vx
- “CVEfeed.io: CVE-2025-4007 Analysis,” CVEfeed, Apr. 2025. [Online]. Available: https://cvefeed.io/vuln/detail/CVE-2025-4007
