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Fencer Vulns
high 7.5

CVE-2021-25633 json

Content Manipulation with Double Certificate Attack

published 2021-10-11 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12529

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

LibreOffice supports digital signatures of ODF documents and macros within documents, presenting visual aids that no alteration of the document occurred since the last signing and that the signature is valid. An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to create a digitally signed ODF document, by manipulating the documentsignatures.xml or macrosignatures.xml stream within the document to combine multiple certificate data, which when opened caused LibreOffice to display a validly signed indicator but whose content was unrelated to the signature shown. This issue affects: The Document Foundation LibreOffice 7-0 versions prior to 7.0.6; 7-1 versions prior to 7.1.2.

Patch / fix

  • The Document Foundation LibreOffice 7.0.6, 7.1.2
  • libreoffice Debian 14, Debian 13, Debian 12 1:7.2.0-2

debian advisories DEBIAN-CVE-2021-25633

  • libreoffice Ubuntu 20.04 LTS 1:6.4.7-0ubuntu0.20.04.2

ubuntu advisories UBUNTU-CVE-2021-25633

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libreoffice RHEL 8 1:6.4.7.2-10.el8
  • autocorr-af RHEL 8 1:6.4.7.2-10.el8
  • autocorr-bg RHEL 8 1:6.4.7.2-10.el8
  • autocorr-ca RHEL 8 1:6.4.7.2-10.el8
  • autocorr-cs RHEL 8 1:6.4.7.2-10.el8
  • autocorr-da RHEL 8 1:6.4.7.2-10.el8
  • autocorr-de RHEL 8 1:6.4.7.2-10.el8
  • autocorr-en RHEL 8 1:6.4.7.2-10.el8

red hat advisories RHSA-2022:1766

  • autocorr-af AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-bg AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-ca AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-cs AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-da AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-de AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-en AlmaLinux 8 1:6.4.7.2-10.el8.alma
  • autocorr-es AlmaLinux 8 1:6.4.7.2-10.el8.alma

almalinux advisories ALSA-2022:1766

  • libreoffice Rocky Linux 8 1:6.4.7.2-10.el8

rocky linux advisories RLSA-2022:1766

  • libreoffice Alpine 3.24, Alpine 3.23, Alpine 3.22 +7 more 7.2.2.2-r0

alpine advisories ALPINE-CVE-2021-25633

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-25633 updated cvss 7.1

libreoffice: Content Manipulation with Double Certificate Attack

  • Red Hat Enterprise Linux 6 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +60 more Red Hat Enterprise Linux 7 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +105 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +98 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 8) autocorr-af 6.4.7.2-10.el8, autocorr-bg 6.4.7.2-10.el8, autocorr-ca 6.4.7.2-10.el8, autocorr-cs 6.4.7.2-10.el8, autocorr-da 6.4.7.2-10.el8, autocorr-de 6.4.7.2-10.el8, +95 more Red Hat Enterprise Linux CRB (v. 8) libreoffice-sdk 6.4.7.2-10.el8
    fixed: vendor fix RHSA-2022:1766
  • Red Hat Enterprise Linux 9 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +101 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • The Document Foundation LibreOffice

Classification

Weakness
  • CWE-295 Improper Certificate Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.