CVE-2025-28221
Published: 28 March 2025
Summary
CVE-2025-28221 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Tenda W6-S Firmware. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 15.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
Tenda W6_S firmware version 1.0.0.4_510 contains a buffer overflow vulnerability in the set_local_time function, tracked as CWE-120. The flaw is triggered when an attacker supplies a crafted time parameter in a POST request that is passed directly to the web server binary, resulting in a crash.
Unauthenticated remote attackers can exploit the issue over the network with low complexity to cause a denial-of-service condition that takes down the device's web server. The vulnerability is rated 7.5 under CVSS 3.1, with the impact limited to high availability loss and no confidentiality or integrity effects.
The current EPSS score stands at 0.0207 with an identical peak value, indicating limited observed exploitation interest. A technical analysis of the flaw, including reproduction details, is published in a GitHub repository.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-8621
Vulnerability details
Tenda W6_S v1.0.0.4_510 has a Buffer Overflow vulnerability in the set_local_time function, which allows remote attackers to cause web server crash via parameter time passed to the binary through a POST request.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in the router web server's set_local_time function allows remote unauthenticated exploitation to crash the service, directly mapping to application/system exploitation for endpoint denial of service.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SI-10 directly prevents buffer overflows by requiring validation of inputs such as the unvalidated 'time' parameter in POST requests to the set_local_time function.
SI-2 ensures timely flaw remediation, including patching the buffer overflow vulnerability in the Tenda W6_S firmware to eliminate the crash condition.
SI-16 mitigates buffer overflow exploits through memory protections that prevent crashes or unauthorized execution from malformed inputs.