CVE-2020-12803Network attack vector

Local file overwrite via unrestricted XForms URI

Published Jun 8, 2020 · Updated Sep 16, 2024

Improper input validation in XForms handling in LibreOffice before 6.4.4 allows remote attackers to overwrite local files via crafted ODF forms. The form-submission path accepts attacker-supplied file: URIs as destinations and writes submitted form data to those local paths without restricting schemes to HTTP or HTTPS. A user must open the document and submit its form; the demonstrated consequence is modification of files writable by that user, not code execution.

CVSS severity6.5
Medium
EPSS probability1.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in XForms handling in LibreOffice before 6.4.4 allows remote attackers to overwrite local files via crafted ODF forms. The form-submission path accepts attacker-supplied file: URIs as destinations and writes submitted form data to those local paths without restricting schemes to HTTP or HTTPS. A user must open the document and submit its form; the demonstrated consequence is modification of files writable by that user, not code execution.

The record

CVE
CVE-2020-12803
Published
Jun 8, 2020
Updated
Sep 16, 2024
Vendor
The Document Foundation
Product
LibreOffice
Classifications
CWE-20, T1565.001, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2020CVE 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

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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 <6.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Document Foundation · LibreOfficeversion=unspecified <6.4.4

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.001Data Manipulation: Stored Data Manipulation
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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