The most probable attack vector used in the security breach is buffer overflow. Buffer overflow is a condition that occurs when a program attempts to write more data to a fixed-length memory space, or buffer, than it can hold. Buffer overflow can corrupt the adjacent memory locations, which may contain important data or instructions for the program. Buffer overflow can be exploited by attackers to inject malicious code into the buffer or another location, and redirect the program flow to execute the malicious code. Buffer overflow can compromise the security, functionality, or performance of the system, or even render it unusable or inaccessible. Buffer overflow can be caused by weaknesses in the software code, design, or configuration, which can be prevented by applying proper software change control and security patch management practices.