GHSA-gm8q-m8mv-jj5m Unstructured has Path Traversal via Malicious MSG Attachment that Allows Arbitrary File Write

• PyPI unstructured: < 0.18.18 → fixed in 0.18.18

A Path Traversal vulnerability in the `partition_msg` function allows an attacker to write or overwrite arbitrary files on the filesystem when processing malicious MSG files with attachments. ## Impact An attacker can craft a malicious .msg file with attachment filenames containing path traversal sequences (e.g., `../../../etc/cron.d/malicious`). When processed with `process_attachments=True`, the library writes the attachment to an attacker-controlled path, potentially leading to: • Arbitrary file overwrite • Remote code execution (via overwriting configuration files, cron jobs, or Python packages) • Data corruption • Denial of service ## Affected Functionality The vulnerability affects the MSG file partitioning functionality when `process_attachments=True` is enabled. ## Vulnerability Details The library does not sanitize attachment filenames in MSG files before using them in file write operations, allowing directory traversal sequences to escape the intended output directory. ## Workarounds Until patched, users can: • Set `process_attachments=False` when processing untrusted MSG files • Avoid processing MSG files from untrusted sources • Implement additional filename validation before processing