5.5

CVE-2021-25635: libreoffice Improper Certificate Validation

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2021-25635
Published 21-03-2025Last modified 21-03-2025
Open JSON

Vulnerability summary

CVE-2021-25635 is a medium (CVSS 5.5) Improper Certificate Validation vulnerability in libreoffice. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 2.8% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.14%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2
MGASA-2021-0471RHSA-2022:1766

Timeline

  1. 21-03-2025
    PublishedVulnerability first disclosed.
  2. 21-03-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

0.00 pp

From 0.14% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.14%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Libreoffice1 product
  • libreoffice≥ 7.0.0, < 7.0.5.1 | ≥ 7.1.0.0, ≤ 7.1.1.1
The document foundation1 product
Ubuntu1 product
  • libreoffice< 1:7.2.1-0ubuntu3

3 vendors · 3 products

References

5 links