Mercurycom Mr816 Firmware vulnerabilities

A stored Cross site scripting (XSS) vulnerability in the Mercury MR816v2 (081C3114 4.8.7 Build 110427 Rel 36550n) router allows a remote attacker on the LAN to inject JavaScript into the router's management UI by submitting a malicious hostname. The injected script is stored and later executed in the context of an administrator's browser (for example after DHCP release/renew triggers the interface to display the stored hostname). Because the management interface uses weak/basic authentication and does not properly protect or isolate session material, the XSS can be used to exfiltrate the admin session and perform administrative actions.

A buffer overflow in the Mercury MR816v2 (081C3114 4.8.7 Build 110427 Rel 36550n) occurs when the device accepts and stores excessively long hostnames from LAN hosts without proper length validation. The affected code performs unchecked copies/concatenations into fixed-size buffers. A crafted long hostname can overflow the buffer, cause a crash (DoS) and potentially enabling remote code execution.