CloakBrowser: Unauthenticated path traversal via fingerprint parameter in cloakserve leads to arbitrary directory deletion

The cloakserve CDP multiplexer uses the user-supplied fingerprint query parameter directly as a filesystem path component when creating Chrome profile directories. An unauthenticated attacker who can reach the cloakserve port can supply a crafted fingerprint value containing path traversal sequences to resolve user_data_dir outside the configured data_dir. When Chrome fails to start or the process is cleaned up, shutil.rmtree() deletes the traversed path, resulting in arbitrary directory deletion.

Additionally, cloakserve bound to 0.0.0.0 by default, making it network-exposed.

Impact

An attacker with network access to the cloakserve port can delete arbitrary directories accessible to the service user.

Patches

Fixed in v0.3.28.

Mitigations

• Upgrade to v0.3.28 or later
• Restrict network access to the cloakserve port