Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Next.js versions before 9.3.2 and 9.3.2-canary.0 to 9.3.2-canary.7 have a directory traversal vulnerability. Attackers could craft special requests to access files in the dist directory (.next). This does not affect files outside of the dist directory (.next). In general, the dist directory only holds build assets unless your application intentionally stores other assets under this directory. This issue is fixed in version 9.3.2.
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.