#VU57212 Improper Verification of Cryptographic Signature in LibreOffice - CVE-2021-25635

Vulnerability identifier: #VU57212

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-25635

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
LibreOffice
Client/Desktop applications / Office applications

Vendor: LibreOffice

Description

The vulnerability allows a remote user to perform spoofing attack.

The vulnerability exists due to application does not properly check for digital signatures of ODF files. A remote attacker can change the signature algorithm in the document 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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

LibreOffice: before 7.0.5.1, 7.1.1.1, 7.0.5.1, 7.0.5.1

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External links
https://www.libreoffice.org/about-us/security/advisories/cve-2021-25635/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.