CVE-2021-4069Public exploit

Memory corruption via stale open-command line pointer

Published Dec 6, 2021 · Updated Aug 3, 2024

Use-after-free in Vim before 8.2.3741 allows local users to corrupt memory or crash the editor through a crafted :open pattern. The ex_open function retains a pointer to the current line while mark lookup can flush that line, then uses the stale pointer for matching. Triggering requires execution of the crafted Ex command; the demonstrated regression case accesses freed memory, while broader code execution is not established.

CVSS severity7.8
High
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Vim before 8.2.3741 allows local users to corrupt memory or crash the editor through a crafted :open pattern. The ex_open function retains a pointer to the current line while mark lookup can flush that line, then uses the stale pointer for matching. Triggering requires execution of the crafted Ex command; the demonstrated regression case accesses freed memory, while broader code execution is not established.

The record

CVE
CVE-2021-4069
Published
Dec 6, 2021
Updated
Aug 3, 2024
Vendor
Vim
Product
Vim
Classifications
CWE-416, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <8.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Vim · Vimversion=unspecified <8.2

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.3huntr.devCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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