nbconvert: Arbitrary file write through path traversal in cell output filenames when exporting to md, latex, rst and asciidoc
nbconvert <= v7.17.1 has an arbitrary file write vulnerability due to a path traversal in ipynb cell output metadata, more specifically on the filename attribute. Vulnerable converters : –to markdown, –to latex, –to rst, –to asciidoc. In ExtractOutputPreprocessor, extractoutput.py:116-119 joins attacker-controlled path to output_files_dir with no canonicalization check, enabling arbitrary file write. This is a sibling vulnerability of https://github.com/advisories/GHSA-4c99-qj7h-p3vg.