Cytel Studio version 9.0 and earlier is vulnerable to a stack-based buffer overflow triggered by parsing a malformed .CY3 file. The vulnerability occurs when the application copies user-controlled strings into a fixed-size stack buffer (256 bytes) without proper bounds checking. Exploitation allows arbitrary code execution when the crafted file is opened.
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).