{"id":"CVE-2021-25636","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-25636","generatedAt":"2026-10-27T20:21:06.895Z","title":"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…","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.","published":"2022-02-24T15:15:22.000Z","lastModified":"2026-06-17T03:42:16.000Z","status":"Modified","sourceIdentifier":"security@documentfoundation.org","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-347","CWE-295"],"affected":["libreoffice/libreoffice","fedoraproject/fedora"],"epss":{"score":0.00954,"percentile":0.61114,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"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."},"changes":[],"references":[{"url":"https://lists.debian.org/debian-lts-announce/2023/03/msg00022.html","source":"security@documentfoundation.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NE6UIBCPZWRBWPSEGJOPNWPPT3CCMVH2/","source":"security@documentfoundation.org"},{"url":"https://www.libreoffice.org/about-us/security/advisories/CVE-2021-25636/","tags":["Vendor Advisory"],"source":"security@documentfoundation.org"},{"url":"https://lists.debian.org/debian-lts-announce/2023/03/msg00022.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NE6UIBCPZWRBWPSEGJOPNWPPT3CCMVH2/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.libreoffice.org/about-us/security/advisories/CVE-2021-25636/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-25636","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}