CVE-2022-39019 is a medium-severity vulnerability affecting M-Files Hubshare versions prior to 3.3.11.3, specifically version 3.3.1.6 as identified. The vulnerability arises from broken access controls in the PDFtron WebviewerUI component integrated within Hubshare. This improper authentication flaw (CWE-287) allows unauthenticated attackers to bypass normal security checks and upload arbitrary, potentially malicious files directly to the application server. Additionally, the vulnerability relates to CWE-434, which concerns unrestricted file upload, further emphasizing the risk of attackers placing harmful files on the server. The CVSS 3.1 base score is 6.3 (medium), with vector AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L, indicating that the attack can be conducted remotely over the network without privileges, requires low attack complexity, and only limited user interaction (likely a victim clicking a link or visiting a crafted URL). The impact affects confidentiality, integrity, and availability to a limited extent, as attackers can upload files that might be used to execute code, exfiltrate data, or disrupt service. No known exploits are currently reported in the wild, but the vulnerability's nature suggests a potential for exploitation if left unpatched. The lack of available patches at the time of reporting underscores the importance of timely updates once released. The vulnerability is rooted in the PDFtron WebviewerUI, a component responsible for rendering PDFs within Hubshare, which is a document management and collaboration platform widely used in enterprise environments for secure file sharing and workflow management.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on M-Files Hubshare for document collaboration and secure file sharing. Successful exploitation could allow attackers to upload malicious files, potentially leading to remote code execution, data leakage, or service disruption. This could compromise sensitive business documents, intellectual property, or personal data protected under GDPR. The breach of confidentiality and integrity could damage organizational reputation and result in regulatory penalties. Additionally, availability impacts could disrupt business operations dependent on Hubshare. Sectors such as finance, legal, healthcare, and government agencies in Europe that use Hubshare for secure document workflows are particularly at risk. The vulnerability's exploitation could also serve as a foothold for lateral movement within corporate networks, escalating the threat beyond the initial compromise. Given the remote and unauthenticated nature of the attack vector, the threat is accessible to a wide range of attackers, increasing the risk profile for affected organizations.

1. Immediate upgrade to M-Files Hubshare version 3.3.11.3 or later once patches are released to address the broken access control vulnerability. 2. Until patches are available, restrict access to the PDFtron WebviewerUI component through network segmentation and firewall rules, limiting exposure to trusted internal networks only. 3. Implement strict input validation and file type restrictions at the web application firewall (WAF) level to block unauthorized file uploads and suspicious payloads targeting the WebviewerUI endpoints. 4. Monitor application logs and network traffic for unusual upload activity or attempts to access the vulnerable component without authentication. 5. Employ endpoint detection and response (EDR) tools to detect and contain any malicious files or behaviors resulting from exploitation attempts. 6. Conduct regular security assessments and penetration testing focused on file upload functionalities to identify and remediate similar weaknesses proactively. 7. Educate users about the risks of interacting with unsolicited links or files related to Hubshare workflows to reduce the likelihood of user interaction facilitating exploitation. 8. Coordinate with M-Files support and subscribe to security advisories to receive timely updates and guidance on vulnerability management.