CVE-2021-25635

Content Manipulation with Certificate Validation Attack

Published Mar 21, 2025 CVSS 4.0 · 5.2 Medium EPSS < 1% KEV · Not listed
Description
An Improper Certificate Validation vulnerability in LibreOffice allowed
an attacker to self sign an ODF document, with a signature untrusted by
the target, then modify it to change the signature algorithm to an
invalid (or unknown to LibreOffice) algorithm and LibreOffice would incorrectly present such a signature with an unknown algorithm as a
valid signature issued by a trusted person


This issue affects LibreOffice: from 7.0 before 7.0.5, from 7.1 before 7.1.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2021-12531 An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to self sign an ODF document, with a signature untrusted by the target, then modify it to change the signature algorithm to an invalid (or unknown to LibreOffice) algorithm and LibreOffice would incorrectly present such a signature with an unknown algorithm as a valid signature issued by a trusted person This issue affects LibreOffice: from 7.0 before 7.0.5, from 7.1 before 7.1.1.
History
Type Values Removed Values Added
First Time appeared Libreoffice
Libreoffice libreoffice
CPEs cpe:2.3:a:libreoffice:libreoffice:*:*:*:*:*:*:*:*
Vendors & Products Libreoffice
Libreoffice libreoffice
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in LibreOffice, where it improperly validated signatures for algorithms that were not verified. This flaw leads to LibreOffice presenting a valid signature when the validity of the signature was not verified. The highest threat from this vulnerability is to confidentiality and integrity. An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to self sign an ODF document, with a signature untrusted by the target, then modify it to change the signature algorithm to an invalid (or unknown to LibreOffice) algorithm and LibreOffice would incorrectly present such a signature with an unknown algorithm as a valid signature issued by a trusted person This issue affects LibreOffice: from 7.0 before 7.0.5, from 7.1 before 7.1.1.
Title libreoffice: Content Manipulation with Certificate Validation Attack Content Manipulation with Certificate Validation Attack
Metrics cvssV4_0

{'score': 5.2, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:H/SI:H/SA:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Document Fdn.
Published
Updated
Mar 21, 2025, 3:13 PM
Reserved
Jan 19, 2021, 10:48 PM
Status
Analyzed
Published
Mar 21, 2025, 3:15 PM
Modified
Jun 17, 2026, 3:42 AM
Severity
Moderate
Public date
Oct 11, 2021, 12:00 AM