The vulnerability stems from incorrect file permissions set during gem installation, not from specific code functions. The root cause was that files in the repository had 0755 permissions (world-executable), which were inherited during gem packaging. When installed, these permissions allowed world-writeable access (0777 in some environments). The fix involved changing file modes to 0644 in the repository (commit 3aac46c). Since this is a packaging/filesystem permission issue rather than a vulnerability in application logic or specific functions, no code functions can be identified as vulnerable with high confidence.