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Fencer Vulns
high 7.3

CVE-2021-3903 json

Heap-based Buffer Overflow in vim/vim

published 2021-10-27 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27132

cvss
7.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

vim is vulnerable to Heap-based Buffer Overflow

Patch / fix

  • vim vim/vim 8.2.3564
  • vim Debian 14, Debian 13, Debian 12 2:8.2.3565-1

debian advisories DEBIAN-CVE-2021-3903

  • vim Ubuntu 18.04 LTS 2:8.0.1453-1ubuntu1.7
  • vim Ubuntu 20.04 LTS 2:8.1.2269-1ubuntu5.4
  • vim Ubuntu 22.04 LTS 2:8.2.3565-1ubuntu2
  • vim Ubuntu Pro 14.04 LTS 2:7.4.052-1ubuntu3.1+esm4
  • vim Ubuntu Pro 16.04 LTS 2:7.4.1689-3ubuntu1.5+esm3

ubuntu advisories UBUNTU-CVE-2021-3903

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 RHEL 9 2:8.2.2637-21.el9
  • vim-X11 RHEL 9 2:8.2.2637-21.el9
  • vim-common RHEL 9 2:8.2.2637-21.el9
  • vim-minimal RHEL 9 2:8.2.2637-21.el9
  • vim-enhanced RHEL 9 2:8.2.2637-21.el9
  • vim-filesystem RHEL 9 2:8.2.2637-21.el9

red hat advisories RHSA-2024:9405

  • vim SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +5 more 9.0.0814-17.9.1
  • vim SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +24 more 8.2.5038-150000.5.21.1

suse advisories SUSE-SU-2022:4619-1SUSE-SU-2022:2102-1

  • vim-X11 AlmaLinux 9 2:8.2.2637-21.el9
  • vim-common AlmaLinux 9 2:8.2.2637-21.el9
  • vim-minimal AlmaLinux 9 2:8.2.2637-21.el9
  • vim-enhanced AlmaLinux 9 2:8.2.2637-21.el9
  • vim-filesystem AlmaLinux 9 2:8.2.2637-21.el9

almalinux advisories ALSA-2024:9405

  • vim Rocky Linux 9 2:8.2.2637-21.el9

rocky linux advisories RLSA-2024:9405

  • vim Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 8.2.3567-r0

alpine advisories ALPINE-CVE-2021-3903

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 8.2.3582-1
  • gvim Arch Linux 8.2.3582-1

arch linux advisories AVG-2472

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-2021-3903 updated cvss 5.5

vim: heap-based buffer overflow vulnerability

  • 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
    affected: workaround, no fix planned “Do not run untrusted vim scripts with -s {scriptin} as it is never safe to do so.”
  • Red Hat Enterprise Linux AppStream (v. 9) vim-X11 8.2.2637-21.el9, vim-common 8.2.2637-21.el9, vim-enhanced 8.2.2637-21.el9 Red Hat Enterprise Linux BaseOS (v. 9) vim 8.2.2637-21.el9, vim-minimal 8.2.2637-21.el9, vim-filesystem 8.2.2637-21.el9
    fixed: vendor fix “Do not run untrusted vim scripts with -s {scriptin} as it is never safe to do so.” RHSA-2024:9405
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/openshift-hive-rhel8 Red Hat Enterprise Linux 8 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

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/35738a4f-55ce-446c-b836-2fb0b39625f8 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 7.3 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/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.