CVE-2023-1170Public exploit

Memory corruption via negative Visual-block spacing

Published Mar 3, 2023 · Updated Mar 7, 2025

Heap-buffer overflow in Vim before 9.0.1376 allows local users to crash the editor by performing a put in Visual block mode. In src/register.c, do_put() accepts a negative spaces value as true and converts it to size_t for vim_memset(), causing a large out-of-bounds heap write; it also leaves the cursor beyond the line terminator. Triggering requires user interaction with Visual block mode and virtual editing; the invalid memory access can crash Vim and corrupt memory in the editor process.

CVSS severity6.6
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in Vim before 9.0.1376 allows local users to crash the editor by performing a put in Visual block mode. In src/register.c, do_put() accepts a negative spaces value as true and converts it to size_t for vim_memset(), causing a large out-of-bounds heap write; it also leaves the cursor beyond the line terminator. Triggering requires user interaction with Visual block mode and virtual editing; the invalid memory access can crash Vim and corrupt memory in the editor process.

The record

CVE
CVE-2023-1170
Published
Mar 3, 2023
Updated
Mar 7, 2025
Vendor
Vim
Product
Vim
Classifications
CWE-122
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 7, 2025Record 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 <9.0.1376

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Vim · Vimversion=unspecified <9.0.1376

Published CVSS scores

7.3huntr.devCVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
6.6NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow

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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