What’s Vulnerable › Vulnerabilities

CVE-2021-28856

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-04-14 · updated 2026-06-17
• Weakness: CWE-369

Description

In Deark before v1.5.8, a specially crafted input file can cause a division by zero in (src/fmtutil.c) because of the value of pixelsize.

Affected products

• Entropymine Deark: before 1.5.8 — fixed in 1.5.8

How to fix

Upgrade to a fixed version: Entropymine Deark 1.5.8. Check the vendor advisory for mitigations.

References

• https://fatihhcelik.github.io/posts/Division-By-Zero-Deark/
• https://github.com/fuzzing2026/CVE-PoCs/tree/main/deark-CVE-2021-28856
• https://github.com/jsummers/deark/commit/62acb7753b0e3c0d3ab3c15057b0a65222313334
• https://fatihhcelik.github.io/posts/Division-By-Zero-Deark/
• https://github.com/jsummers/deark/commit/62acb7753b0e3c0d3ab3c15057b0a65222313334

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