CVE-2025-14199 is a vulnerability identified in the Verysync file synchronization software, specifically affecting versions 2.21.0 through 2.21.3. The flaw resides in the Web Administration Module, within an unspecified function related to the file path /rest/f/api/resources/f96956469e7be39d/tmp/text.txt?override=false. This vulnerability permits unrestricted file uploads, allowing an attacker to remotely upload arbitrary files without authentication or user interaction. The attack vector is network-based (AV:N), with low attack complexity (AC:L), and requires low privileges (PR:L), but no user interaction (UI:N). The impact on confidentiality, integrity, and availability is low individually but combined can lead to significant compromise if the uploaded files are malicious scripts or executables. The vulnerability is rated medium severity with a CVSS 4.0 score of 5.3. The vendor has not responded to disclosure requests, and no patches are currently available. Exploit code has been published, increasing the likelihood of exploitation. The flaw could enable attackers to execute arbitrary code, escalate privileges, or disrupt services by uploading malicious payloads to the affected endpoint. This vulnerability is particularly concerning for environments where Verysync is exposed to untrusted networks or internet-facing interfaces. Since the Web Administration Module is involved, administrative functions may be at risk, potentially allowing attackers to gain control over the system or access sensitive data.

For European organizations, the unrestricted upload vulnerability in Verysync could lead to unauthorized system access, data breaches, or service disruptions. Organizations using Verysync for file synchronization or web administration may face risks of remote code execution or malware deployment. This could impact confidentiality if sensitive files are accessed or exfiltrated, integrity if files or configurations are altered, and availability if services are disrupted. Sectors such as finance, healthcare, and critical infrastructure relying on Verysync for internal or external file management may experience operational and reputational damage. The lack of vendor response and patches increases exposure time, raising the risk of exploitation especially as proof-of-concept exploits are publicly available. Attackers could leverage this vulnerability to establish persistent footholds or pivot within networks, complicating incident response and recovery efforts.

European organizations should immediately restrict network access to the vulnerable Web Administration Module endpoint, ideally limiting it to trusted internal IP addresses or VPN connections. Implement strict firewall rules and web application firewall (WAF) policies to detect and block suspicious file upload attempts targeting the /rest/f/api/resources/f96956469e7be39d/tmp/text.txt endpoint. Conduct thorough monitoring and logging of file uploads and administrative actions to detect anomalous behavior. Disable or remove unnecessary web administration interfaces if possible. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts. Until an official patch is released, consider deploying application-layer proxies or reverse proxies to sanitize or block unauthorized uploads. Educate administrators about the vulnerability and ensure rapid incident response readiness. Regularly audit Verysync deployments for unauthorized files or modifications. Engage with the vendor for updates and apply patches promptly once available.