CVE-2020-37124 | B64dec 1.1.2 contains a buffer overflow vulnerability that a… | CVSS 9.8 CRITICAL

Description

B64dec 1.1.2 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by overwriting Structured Exception Handler (SEH) with crafted input. Attackers can leverage an egg hunter technique and carefully constructed payload to inject and execute malicious code during base64 decoding process.

Metadata

CVE ID: CVE-2020-37124
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-02-03 16:27 UTC
Published: 2026-02-05 16:13 UTC
Last updated: 2026-02-06 20:34 UTC
Primary CWE: CWE-121
Stack-based Buffer Overflow
Vendor / Product: 4Mhz / B64dec
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
4Mhz	B64dec	—	1.1.2

Weakness (CWE)

CWE	Source	Description
CWE-121	cna	Stack-based Buffer Overflow

CVSS scores (2)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.4	HIGH	4.0	cna	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References (3)

ExploitDB-48317 https://www.exploit-db.com/exploits/48317
Product Webpage http://4mhz.de/b64dec.html
VulnCheck Advisory: B64dec 1.1.2 - Buffer Overflow (SEH Overflow + Egg Hunter) https://www.vulncheck.com/advisories/bdec-buffer-overflow-seh-overflow-egg-hunter