CVE-2026-107092 in NexoPOS
Summary
by MITRE • 10/26/2026
NexoPOS v6.2.4 is vulnerable to Directory Traversal via the api/update endpoint.
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Analysis
by VulDB Data Team • 10/26/2026
The vulnerability identified in NexoPOS version 6.2.4 represents a critical security flaw classified as a Path Traversal or Directory Traversal issue, specifically located within the application's API update endpoint. This type of vulnerability arises when an application fails to properly sanitize user-supplied input before using it to construct file paths on the underlying operating system. In this specific instance, the api/update endpoint accepts parameters that are intended for updating configuration files or internal data structures but lacks adequate validation mechanisms to ensure these inputs remain within their designated directory boundaries. An attacker can exploit this weakness by manipulating the input parameter with sequences such as dot-dot-slash (../) combined with absolute path references to navigate outside of the web root and access sensitive system files that are not intended for public or even authenticated user modification.
From a technical perspective, the flaw stems from insufficient abstraction between the application logic and the file system operations. When the server processes the request sent to the update endpoint, it directly incorporates parts of the input into filesystem read or write calls without verifying whether the resulting path resolves to a location within the expected application directory structure. This allows for arbitrary file reads if the operation involves reading configuration data, or potentially arbitrary file writes if the endpoint permits overwriting existing files with attacker-controlled content. The severity is compounded by the fact that API endpoints are often exposed directly to network traffic and may have different authentication or authorization checks compared to standard web pages, making them attractive targets for automated exploitation tools designed to probe for common misconfigurations in modern web applications.
The operational impact of this vulnerability can be severe depending on the privileges under which the NexoPOS application runs and the sensitivity of files accessible through traversal. If an attacker successfully exploits this flaw, they could read sensitive configuration files containing database credentials, API keys, or internal encryption secrets, leading to a complete compromise of data confidentiality. Furthermore, if write access is possible via the same mechanism, it opens the door for Remote Code Execution (RCE). By overwriting critical application scripts with malicious code, an attacker can achieve full control over the server environment. This aligns closely with CWE-22: Improper Limitation of a Pathname to a Restricted Directory and potentially CWE-434: Unrestricted Upload of File with Dangerous Type if file upload capabilities are involved in the update process.
In terms of threat modeling, this vulnerability maps directly to MITRE ATT&CK techniques related to Collection via Local Network Share or Remote File Inclusion depending on how the server processes external paths. Specifically, it falls under T1083: File and Directory Discovery if used for reconnaissance, but more critically aligns with T1564: Hidden Files and Directories when attempting to obscure malicious changes, or T1204: User Execution if leading to script injection. The exploitation typically requires authentication unless the endpoint is publicly accessible without proper access controls, which would elevate it from a medium-severity issue to critical due to its potential for unauthenticated remote code execution.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The most effective short-term fix involves implementing strict input validation on all parameters passed to the api/update endpoint. Developers should enforce allowlisting of acceptable file paths or use canonicalization techniques to resolve symbolic links and relative path components before performing any filesystem operations. It is crucial to ensure that the resolved absolute path starts with the expected base directory prefix, rejecting any request where this condition fails. Additionally, applying principle of least privilege by running the web application process under a restricted user account can limit the damage even if traversal succeeds.
Long-term remediation requires adopting secure coding practices such as using safe APIs for file handling that abstract away direct path manipulation and implementing comprehensive logging to detect attempts at directory traversal in real-time. Security headers should be configured correctly, and regular penetration testing should include specific tests against API endpoints known to handle file operations. Updating NexoPOS to a patched version where this validation has been implemented by the vendor is the primary recommendation for organizations currently running version 6.2.4 or earlier affected versions. Until patches are applied, network-level controls such as Web Application Firewalls (WAF) can be tuned to block requests containing common traversal patterns like ../ in query parameters or POST bodies targeting this specific endpoint.