AI analysis
Claude Opus · 9 Nov 2026, 10:20 CET
TOTOLINK CA300-PoE firmware buffer overflow in custom module upload handler
TOTOLINK CA300-PoE firmware 6.2c.884 has a remotely reachable buffer overflow in the UploadCustomModule function of its web CGI. Exploitation requires high privileges, but public exploit details exist. Restrict management access and check with TOTOLINK for updated firmware.
In plain terms
The TOTOLINK CA300-PoE is a network device managed through a built-in web interface. In firmware version 6.2c.884, one feature of that interface, used to upload a custom module, does not properly check the size of the data it receives. This is a buffer overflow: the device writes more data into a memory area than it was designed to hold, which can corrupt memory and, in the worst case, let an attacker run their own code on the device.
An attacker would need administrator-level access to the web interface to reach this function, according to the published score. Anyone running this device, especially where its management interface is reachable from untrusted networks or protected by weak or default credentials, should take note.