Buffer overflow in 4mhz B64dec
CVE-2020-37124
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.
Vulnerability class: Buffer Overflow
EPSS: 0.004 (28.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- 4mhz B64dec — versions 1.1.2
Weakness classification (CWE)
References
- disclosure@vulncheck.com (exploit)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2020-37124?
- CVE-2020-37124 is a critical-severity vulnerability in 4mhz B64dec, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-02-05.
- How severe is CVE-2020-37124?
- Critical severity. CVSS v3 base score is 9.8 out of 10.