CVE-2021-4193Public exploit

Process-memory disclosure via unchecked visual column

Published Dec 31, 2021 · Updated Aug 3, 2024

Out-of-bounds read in Vim before 8.2.3901 allows context-dependent attackers to disclose process memory through a crafted file. The getvcol() function calculates a pointer from an unchecked visual-column position that can lie beyond the line's terminating NUL byte. Opening the file and exercising the /%V visual-area atom is required; the read exposes adjacent Vim process memory without modifying data.

CVSS severity5.5
Medium
EPSS probability1.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Vim before 8.2.3901 allows context-dependent attackers to disclose process memory through a crafted file. The getvcol() function calculates a pointer from an unchecked visual-column position that can lie beyond the line's terminating NUL byte. Opening the file and exercising the /%V visual-area atom is required; the read exposes adjacent Vim process memory without modifying data.

The record

CVE
CVE-2021-4193
Published
Dec 31, 2021
Updated
Aug 3, 2024
Vendor
Vim
Product
Vim
Classifications
CWE-125, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 31, 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 <8.2.3901

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Vim · Vimversion=unspecified <8.2.3901

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
5.5huntr.devCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
4.3NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002User Execution: Malicious File

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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