CVE-2025-56815 is a directory traversal vulnerability identified in Datart version 1.0.0-rc.3, specifically affecting the POST /viz/image interface. The vulnerability arises because the server uses the MultipartFile.transferTo() method to save uploaded files directly to a filesystem path that can be influenced by the user. Critically, the application does not enforce strict validation or sanitization of the file name provided during upload. This lack of verification allows an attacker to craft file names containing directory traversal sequences (such as '../') to escape the intended upload directory and write files to arbitrary locations on the server's filesystem. Exploiting this vulnerability could enable an attacker to overwrite or create files outside the designated upload directory, potentially leading to unauthorized file modification, data corruption, or even remote code execution if the attacker can place executable files in sensitive locations. The vulnerability does not currently have a CVSS score assigned, and no known exploits in the wild have been reported as of the publication date (September 24, 2025). However, the nature of directory traversal vulnerabilities, especially those involving file upload mechanisms, typically presents a significant security risk if left unmitigated. The vulnerability affects Datart 1.0.0-rc.3, a specific release candidate version, but the exact scope of affected versions is not fully detailed. The root cause is the unsafe handling of file paths during file upload without proper sanitization or canonicalization, which is a common and well-understood security flaw in web applications handling user-supplied file inputs.

For European organizations using Datart 1.0.0-rc.3, this vulnerability poses a substantial risk to the confidentiality, integrity, and availability of their systems. An attacker exploiting this flaw could overwrite critical application files, configuration files, or place malicious scripts on the server, potentially leading to unauthorized access, data breaches, or service disruption. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and government, could face severe regulatory and reputational consequences if sensitive data is exposed or systems are compromised. Additionally, the ability to write files arbitrarily may facilitate further attacks, including privilege escalation or lateral movement within the network. The absence of known exploits in the wild currently reduces immediate risk, but the vulnerability’s straightforward exploitation path means that attackers could develop exploits rapidly once the vulnerability becomes widely known. Given the increasing reliance on data visualization and analytics platforms like Datart in European enterprises, the potential impact on operational continuity and data security is significant.

To mitigate this vulnerability, organizations should implement strict validation and sanitization of all file names received via the POST /viz/image interface. This includes rejecting or neutralizing directory traversal characters such as '../' or '..\' in file names. Employing canonicalization techniques to resolve and verify the final file path before saving is critical to ensure files are stored only within the intended directory. Additionally, applying the principle of least privilege to the file storage directories—restricting write permissions to only necessary locations—can limit the damage if exploitation occurs. Organizations should monitor for updates or patches from Datart developers and apply them promptly once available. In the interim, deploying web application firewalls (WAFs) with rules to detect and block directory traversal attempts in file uploads can provide an additional layer of defense. Regular security audits and code reviews focusing on file handling routines are recommended to identify and remediate similar vulnerabilities. Finally, logging and alerting on suspicious file upload activities can help detect exploitation attempts early.