Spoofing attack in LibreOffice

1) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU57212

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-25635

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

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 7.1.1.1

External links

http://www.libreoffice.org/about-us/security/advisories/cve-2021-25635/

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.