Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
sspa is a server dedicated to single-page apps. sspa is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
CWE-22 - Path Traversal
Path traversal (or directory traversal), is a vulnerability that allows malicious users to traverse the server's root directory, gaining access to arbitrary files and folders such as application code & data, back-end credentials, and sensitive operating system files. In the worst-case scenario, an attacker could potentially execute arbitrary files on the server, resulting in a denial of service attack. Such an exploit may severely impact the integrity, confidentiality, and availability of an application.