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Fencer Vulns
high 8.6

CVE-2021-3770 json

Heap-based Buffer Overflow in vim/vim

published 2021-09-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27039

cvss
8.6
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

vim is vulnerable to Heap-based Buffer Overflow

Patch / fix

  • vim vim/vim 8.2.3403
  • vim Debian 14, Debian 13, Debian 12 2:8.2.3455-1

debian advisories DEBIAN-CVE-2021-3770

  • vim Ubuntu 20.04 LTS 2:8.1.2269-1ubuntu5.3

ubuntu advisories UBUNTU-CVE-2021-3770

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • vim Alpine 3.24, Alpine 3.23, Alpine 3.22 +11 more 8.2.3437-r0

alpine advisories ALPINE-CVE-2021-3770

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • vim Arch Linux 8.2.3412-1
  • gvim Arch Linux 8.2.3412-1

arch linux advisories AVG-2364

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-3770 updated cvss 7.3

vim: using retab with large value may lead to heap buffer overflow

  • Red Hat Enterprise Linux 6 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 7 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 8 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 9 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/016ad2f2-07c1-4d14-a8ce-6eed10729365 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.6 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • vim vim/vim

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.