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CVE-2021-41253
MEDIUM · CVSS 5.9
EPSS exploitation probability: 0%
Published 2021-11-08T22:15:16.757 · Last modified 2026-06-17T04:08:10.943

Summary

Zydis is an x86/x86-64 disassembler library. Users of Zydis versions v3.2.0 and older that use the string functions provided in `zycore` in order to append untrusted user data to the formatter buffer within their custom formatter hooks can run into heap buffer overflows. Older versions of Zydis failed to properly initialize the string object within the formatter buffer, forgetting to initialize a few fields, leaving their value to chance. This could then in turn cause zycore functions like `ZyanStringAppend` to make incorrect calculations for the new target size, resulting in heap memory corruption. This does not affect the regular uncustomized Zydis formatter, because Zydis internally doesn't use the string functions in zycore that act upon these fields. However, because the zycore string

Affected products

zyantific — zydis

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.