Is CVE-2021-25636 in the CISA KEV catalog?

No. CVE-2021-25636 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-25636?

CVE-2021-25636 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-25636?

CVE-2021-25636 has an EPSS score of 0.97% (57th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-25636?

Upgrade libreoffice on debian 11 to 1:7.0.4-4+deb11u2 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-25636

HIGH

7.5

CVSS v3

NVD

Description

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 contain both "X509Data" and "KeyValue" children of the "KeyInfo" tag, which when opened caused LibreOffice to verify using the "KeyValue" but to report verification with the unrelated "X509Data" value. This issue affects: The Document Foundation LibreOffice 7.2 versions prior to 7.2.5.

CWE-347 CWE-295Improper Certificate Validation

How to fix

Remediation Available

libreofficeDebian

Fixed in:1:7.0.4-4+deb11u2CVE-2021-25636

Fixed in:1:7.3.0-1CVE-2021-25636

libreofficeUbuntu

Fixed in:1:6.0.7-0ubuntu0.18.04.11USN-5330-1

Fixed in:1:6.4.7-0ubuntu0.20.04.4USN-5330-1

libreoffice-coreUbuntu

Fixed in:1:6.0.7-0ubuntu0.18.04.11USN-5330-1

Fixed in:1:6.4.7-0ubuntu0.20.04.4USN-5330-1

LibreOfficeWindows application

Affected:7.2.0 7.2.5Fixed in:7.2.5The Document Foundation

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

0.97%probability of exploitation in 30 days

57thpercentile

Moderate risk: more likely to be exploited than 57% of all known CVEs.

References

Vendor Advisory1

libreoffice.org

Other references2

Related Vulnerabilities

Other CWE-347 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2018-16042	Medium	6.5	82%	-	-
CVE-2025-59718	Critical	9.8	66%	KEV	Fix
CVE-2025-25292	Critical	9.8	64%	-	Fix
CVE-2021-22160	Critical	9.8	53%	-	Fix
CVE-2013-3900	Medium	5.5	45%	KEV	-
CVE-2018-0114	High	7.5	43%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.