A misused endpoint in Tenda RX3 firmware version 16.03.13.11, specifically /goform/openSchedWifi, can be abused by sending crafted schedStartTime and schedEndTime parameters that trigger a stack-based buffer overflow. The vulnerability originates from improper bounds checking in the handling of these arguments, constituting both CWE-119 and CWE-121 weaknesses. If successfully exploited, the overflow would allow an attacker to overwrite return addresses and execute arbitrary code, leading to full compromise of the device and the local network.

The vulnerability affects Tenda RX3 routers running firmware version 16.03.13.11. The issue does not appear in earlier or later builds according to vendor data, and it is specific to the openSchedWifi functionality exposed on the device’s web interface.

The CVSS base score of 8.7 reflects a critical flaw with high impact, while the EPSS score of less than 1% indicates a low probability of widespread exploitation at the present time. The vulnerability has been publicly released by threat actors, and it can be leveraged remotely without any local interaction. Because it is not listed in the CISA KEV catalog, the exposure is not yet confirmed at a national level, but the remote nature warrants aggressive mitigation.