CVE-2026-50776 in Billetterie
Summary
by MITRE • 08/17/2026
Directory Traversal vulnerability in Pronis Loisirs Billetterie CSE - < 04/2026 allows a remote attacker to obtain sensitive information and execute arbitrary code.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/17/2026
The identified security flaw represents a critical directory traversal vulnerability within the Pronis Loisirs Billetterie CSE software, specifically affecting versions released prior to April 2026. This type of vulnerability stems from insufficient validation or sanitization of user-supplied input that is used as part of file path construction operations. In typical web application architectures, this often occurs when a system accepts parameters such as filenames or directory paths and concatenates them with base directories without ensuring the input remains within expected boundaries. An attacker can exploit this by manipulating these inputs to include special character sequences, commonly known as dot-dot-slash sequences in Unix-like systems or backslashes in Windows environments, which instruct the operating system to traverse upward from the current working directory into parent directories. This allows the remote attacker to bypass intended access controls and reach files located outside of the web root or application-specific sandboxed areas.
The operational impact of this vulnerability is severe due to its potential for both information disclosure and arbitrary code execution, as indicated in the initial report. By leveraging the traversal capability, an adversary can read sensitive configuration files that may contain database credentials, API keys, internal network topology details, or proprietary business logic. The ability to execute arbitrary code suggests a more complex exploitation chain where the attacker might not only read static content but also manipulate dynamic processes. This could involve uploading malicious scripts into accessible directories and then triggering their execution through specific application functions, thereby gaining full control over the underlying server infrastructure. Such compromise can lead to complete system takeover, data exfiltration, defacement of public-facing interfaces, or use of the compromised host as a pivot point for further attacks against internal network resources.
From a technical classification perspective, this vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which is part of the broader category of path traversal flaws often associated with CWE-73 in older classifications or mapped under injection-related weaknesses depending on implementation specifics. In terms of offensive security frameworks like MITRE ATT&CK, this behavior corresponds to techniques involving File and Directory Discovery (T1083) for reconnaissance and potentially Command Line Interface Execution (T1059) if the traversal leads directly to script execution via server-side interpreters or included files. The severity is amplified by the fact that it allows remote exploitation without authentication in many default configurations, making it a high-priority target for automated scanning tools and opportunistic attackers seeking quick wins against unpatched systems.
Mitigation strategies must focus on immediate remediation of the source code alongside defensive infrastructure adjustments. Developers should implement strict input validation to ensure that all file path parameters consist only of alphanumeric characters and do not contain directory traversal sequences or absolute paths unless explicitly required by design, in which case canonicalization checks are mandatory before any filesystem interaction occurs. Utilizing allowlists for permitted filenames is significantly more secure than relying on blocklists of malicious patterns. Furthermore, the application should run with the principle of least privilege, ensuring that the web server process does not have write access to directories outside its designated root and read access only to necessary configuration files. On the infrastructure level, deploying a Web Application Firewall can provide an additional layer of defense by detecting and blocking requests containing traversal patterns such as ../ or ..\ before they reach the application logic. Regular security audits and static code analysis tools should be integrated into the development lifecycle to prevent similar flaws from being introduced in future updates.