Description
A stack buffer overflow vulnerability exists in the ToToLink LR1200GB (V9.1.0u.6619_B20230130) and NR1800X (V9.1.0u.6681_B20230703) Router firmware within the cstecgi.cgi binary (sub_42F32C function). The web interface reads the "lang" parameter and constructs Help URL strings using sprintf() into fixed-size stack buffers without proper length validation. Maliciously crafted input can overflow these buffers, potentially leading to arbitrary code execution or memory corruption, without requiring authentication.