CVE-2020-37124 B64dec 1.1.2 - Buffer Overflow (SEH Overflow + Egg Hunter)
Attackers can execute arbitrary code via a buffer overflow in the B64dec library during base64 decoding using SEH overwrite techniques.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-37124?
CVE-2020-37124 is a high-severity memory corruption vulnerability in 4Mhz B64dec, published on 5 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-121
Which versions are affected by CVE-2020-37124?
How do I fix CVE-2020-37124?
No fix has been published for CVE-2020-37124 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2020-37124 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37124 exists.
Sources
Also known as GHSA-vh82-45mm-g28j.