Executive brief
A buffer overflow vulnerability exists in the Tenda W20E enterprise router, a device used to provide wireless networking for small businesses. By sending a specially crafted web request, an attacker can crash the device's management service. This results in a denial-of-service condition, disrupting network administration and potentially causing device instability.
Technical details
A stack-based buffer overflow vulnerability exists in the Tenda W20E router firmware version v15.11.0.6. The flaw is located within the 'formCropAndSetWewifiPic' function, where the 'picCropName' HTTP parameter is retrieved via 'websGetVar' and subsequently passed to 'sprintf' without adequate bounds checking. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request containing an overly long string in the 'picCropName' parameter. Successful exploitation leads to a process crash or device instability, resulting in a Denial of Service (DoS). While the advisory focuses on DoS, stack overflows of this nature can sometimes be leveraged for remote code execution.
Affected products
- Tenda W20E v15.11.0.6
Timeline
- 2026-03-19: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure
- 2026-06-09: advisory: NVD published date