VYPR
High severity7.1NVD Advisory· Published Mar 23, 2021· Updated Jun 17, 2026

CVE-2021-21401

CVE-2021-21401

Description

Nanopb is a small code-size Protocol Buffers implementation in ansi C. In Nanopb before versions 0.3.9.8 and 0.4.5, decoding a specifically formed message can cause invalid free() or realloc() calls if the message type contains an oneof field, and the oneof directly contains both a pointer field and a non-pointer field. If the message data first contains the non-pointer field and then the pointer field, the data of the non-pointer field is incorrectly treated as if it was a pointer value. Such message data rarely occurs in normal messages, but it is a concern when untrusted data is parsed. This has been fixed in versions 0.3.9.8 and 0.4.5. See referenced GitHub Security Advisory for more information including workarounds.

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Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
nanopbPyPI
>= 0.3.2, < 0.3.9.80.3.9.8
nanopbPyPI
>= 0.4.0, < 0.4.50.4.5

Affected products

3

Patches

Vulnerability mechanics

References

8

News mentions

0

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