The vulnerability in zanllp infinite-image-browsing stems from the to_abs_path function using os.path.normpath, which collapses dot segments but does not resolve symbolic links. This allows a symlink placed inside a scanned directory to bypass containment checks performed by is_path_trusted, as the symlink appears to be within the directory but points outside it. When FileResponse serves the file, it follows the symlink, disclosing files outside the intended directory. Access control is conditionally enabled based on environment variables and startup options, affecting whether the vulnerability is mitigated. The remediation is to replace os.path.normpath with os.path.realpath to resolve symlinks correctly.

An attacker can exploit this vulnerability to read arbitrary files on the host system by placing symbolic links in image directories that point to sensitive files outside those directories. This can lead to unauthorized disclosure of sensitive information such as system password files. The risk is higher in standalone deployments where access control is disabled, allowing access to all readable files. Network-exposed deployments with access control enabled are less affected but still vulnerable if the configuration falls back to enabling access control improperly.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability can be mitigated by ensuring that path resolution uses os.path.realpath to resolve symbolic links before access checks. Additionally, configuring the environment variable IIB_ACCESS_CONTROL to 'enable' and using network-exposed deployment options (share, ngrok, listen, server_name) activates confinement, reducing exposure. Until an official fix is available, avoid running standalone instances without access control enabled.