PT-2026-27368 · 4Mhz · Base64 Decoder

Published 2026-03-24 · Updated 2026-03-24 · CVE-2019-25634

Mitre

CVSS v3.1

8.4

High

AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Base64 Decoder 1.1.2 contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by triggering a structured exception handler (SEH) overwrite. Attackers can craft a malicious input file that overflows a buffer, overwrites the SEH chain with a POP-POP-RET gadget address, and uses an egghunter payload to locate and execute shellcode for code execution.

Exploit

Fix

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

CVE-2019-25634

Affected Products

Base64 Decoder

References · 5

• 🔥 https://exploit-db.com/exploits/46625 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2019-25634 · Security Note
• http://4mhz.de/b64dec.html · Note
• https://vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter · Note
• http://4mhz.de/download.php?file=b64dec-1-1-2.zip · Note