CVE-2022-39016 is a high-severity vulnerability identified in M-Files Hubshare versions prior to 3.3.10.9, specifically affecting version 3.3.1.6. The vulnerability arises from improper input validation (CWE-20) and cross-site scripting (CWE-79) issues within the PDFtron component used by Hubshare. An authenticated attacker can exploit this flaw by uploading a specially crafted PDF file containing malicious JavaScript code. This JavaScript injection enables the attacker to perform an account takeover, compromising the confidentiality and integrity of user accounts. The vulnerability is characterized by a CVSS 3.1 base score of 8.2, indicating high severity. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), and limited privileges (PR:L) with user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality is high, with partial impacts on integrity and availability. Although no known exploits are reported in the wild, the vulnerability presents a significant risk due to the potential for account compromise and subsequent unauthorized access to sensitive documents and data managed within Hubshare. The lack of a patch link suggests that users should verify the availability of updates from M-Files and apply them promptly to mitigate risk.

For European organizations utilizing M-Files Hubshare, this vulnerability poses a substantial risk to data security and operational integrity. Hubshare is often used for secure document sharing and collaboration, meaning an account takeover could lead to unauthorized access to sensitive corporate documents, intellectual property, and personal data protected under GDPR. The compromise of user accounts could facilitate lateral movement within organizational networks, data exfiltration, and potential regulatory non-compliance due to data breaches. The requirement for authentication and user interaction somewhat limits exploitation but does not eliminate risk, especially in environments where users have elevated privileges or where social engineering can be leveraged to induce interaction. Given the high confidentiality impact, organizations in sectors such as finance, legal, healthcare, and government within Europe could face significant reputational and financial damage if exploited.

European organizations should immediately verify their Hubshare version and upgrade to version 3.3.10.9 or later where the vulnerability is addressed. In the absence of an official patch, organizations should implement strict file upload controls, including scanning PDFs for embedded scripts and restricting upload permissions to trusted users only. Employing Content Security Policy (CSP) headers can help mitigate the impact of injected scripts by restricting script execution contexts. Additionally, monitoring user activity for anomalous behavior indicative of account takeover attempts is critical. Organizations should enforce multi-factor authentication (MFA) to reduce the risk of compromised credentials being abused. Regular security awareness training to educate users about the risks of interacting with suspicious documents can reduce the likelihood of successful exploitation. Finally, network segmentation and least privilege principles should be applied to limit the potential damage from compromised accounts.