CVE-2021-25631Public exploitNetwork attack vector

Code execution via hyperlink denylist bypass

Published May 3, 2021 · Updated Sep 16, 2024

Code execution in LibreOffice 7.0 before 7.0.5 and 7.1 before 7.1.2 allows remote attackers to execute programs via crafted document hyperlinks on Windows. The hyperlink handler passes a manipulated link to ShellExecute after an incomplete executable-extension denylist check, allowing an executable type to launch. Exploitation requires a victim to open the document and CTRL-click the hyperlink; the resulting process runs with the user's Windows privileges.

CVSS severity8.8
High
EPSS probability5.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code execution in LibreOffice 7.0 before 7.0.5 and 7.1 before 7.1.2 allows remote attackers to execute programs via crafted document hyperlinks on Windows. The hyperlink handler passes a manipulated link to ShellExecute after an incomplete executable-extension denylist check, allowing an executable type to launch. Exploitation requires a victim to open the document and CTRL-click the hyperlink; the resulting process runs with the user's Windows privileges.

The record

CVE
CVE-2021-25631
Published
May 3, 2021
Updated
Sep 16, 2024
Vendor
The Document Foundation
Product
LibreOffice
Classifications
CWE-184, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=7.0 <7.0.5
  2. Affected versionversion=7.1 <7.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Document Foundation · LibreOfficeversion=7.0 <7.0.5; version=7.1 <7.1.2

Published CVSS scores

9.3NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-184Incomplete Denylist
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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