Authenticated arbitrary file write via symlink traversal

Path traversal in the File Manager in pgAdmin Development Team pgAdmin 4 before 9.15 allows remote authenticated users to write files. check_access_permission normalizes an attacker-controlled storage path with os.path.abspath but does not resolve symbolic links before the kernel follows them during the write. A user able to place a symlink in that user's storage directory can overwrite any path writable by the pgAdmin process, potentially corrupting application data or interrupting the service.