VulnerabilityModified

CVE-2021-25636

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…

HIGH 7.5EPSS 0.95%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.95%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS: 0.95% probability · 59th percentile
CISA KEV: Not listed
Weakness: CWE-347, CWE-295
Affected: libreoffice/libreoffice · fedoraproject/fedora
Source: security@documentfoundation.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.