CVE-2021-25635

Content Manipulation with Certificate Validation Attack

MEDIUM
5.5
CVSS Score
Published: March 21, 2025 at 02:52 PM UTC
Updated: June 17, 2026 at 03:42 AM UTC
2 products affected across 2 vendorsLibreofficeLibreOffice

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.0.0 ≤ v < 7.0.5.17.1.0.0 ≤ v ≤ 7.1.1.1
7.0 ≤ v < 7.0.57.1 ≤ v < 7.1.17.07.1
Affected range stops below 7.0.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.1.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-295

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