Base64 Decoder version 1.1.2 contains a critical stack-based buffer overflow vulnerability that enables local attackers to execute arbitrary code. The vulnerability can be exploited by crafting malicious input files that overflow a buffer and overwrite the Structured Exception Handler (SEH) chain. Attackers use a POP-POP-RET gadget address to control execution flow and employ an egghunter payload to locate and execute shellcode. This allows complete code execution on the target system. The vulnerability has been assigned CVE-2019-25634 and has exploit code publicly available on Exploit-DB.