Official Product Homepageproduct
http://4mhz.de/b64dec.html CVE-2019-25634
HIGH
Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter
Record summary
CVE-2019-25634 has a selected CVSS score of 8.6 (high); EIP currently links 1 catalogued exploit.
Description
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.
Description source: CVE List
Exploitation context
Available material
- Catalogued exploits
- 1
CISA SSVC decision
ExploitationPoC
AutomatableNo
Technical impactTotal
CISA Coordinator · SSVC 2.0.3 · Evaluated Mar 24, 2026 · Source: CVE List
Affected products and versions
1| Product | Source | Version range | Status |
|---|---|---|---|
Base64 DecoderBrowse 4Mhz / Base64 Decoder | CVE List | 1.1.2 | affected |
Proofs of concept
1Catalogued exploits
ExploitDBBase64 Decoder 1.1.2 - Local Buffer Overflow (SEH Egghunter)ExploitDB exploitby Paolo PeregoNot analyzed1 file
References
5Product Referenceproduct
http://4mhz.de/download.php?file=b64dec-1-1-2.zip nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2019-25634 ExploitDB-46625exploit
https://www.exploit-db.com/exploits/46625 VulnCheck Advisory: Base64 Decoder 1.1.2 Local Buffer Overflow SEH EgghunterThird-party advisory
https://www.vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter