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TI-2020-19259 Aliases CVE-2020-37124GHSA-vh82-45mm-g28j

B64dec 1.1.2 - Buffer Overflow (SEH Overflow + Egg Hunter)

Priority HIGH 78CWE-121Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0042 36th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
4MhzB64dec1.1.2—No fix listedCNA
  • B64dec Vendor4Mhz Affected 1.1.2 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-37124
  2. 2026-10-03 Alias added: GHSA-vh82-45mm-g28j

References

Exploit 1

Other 1

  • TI-2019-15687 Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter CVSS 4.0HIGH 8.6

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences