CVE-2020-20703Public exploit

Editor crash via freed window pointer

Published Jun 20, 2023 · Updated Dec 10, 2024

Use-after-free in Vim 8.1.2135 allows context-dependent attackers to crash the editor by sourcing a crafted Vim script. During win_enter_ext, WinNew or WinEnter autocommands can close the target window, but Vim then dereferences the freed wp window pointer while checking its buffer type. A user must cause the script to be sourced; the upstream report demonstrates a process crash, while the CVE record additionally claims arbitrary code execution.

CVSS severity9.8
Critical
EPSS probability1.51%
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 8.1.2135 allows context-dependent attackers to crash the editor by sourcing a crafted Vim script. During win_enter_ext, WinNew or WinEnter autocommands can close the target window, but Vim then dereferences the freed wp window pointer while checking its buffer type. A user must cause the script to be sourced; the upstream report demonstrates a process crash, while the CVE record additionally claims arbitrary code execution.

The record

CVE
CVE-2020-20703
Published
Jun 20, 2023
Updated
Dec 10, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1203
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 10, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
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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