Mammoth.js 1.3.0 before 1.12.3 contains a regular expression denial of service vulnerability in the style map tokeniser in lib/styles/parser/tokeniser.js due to overlapping regex alternatives. Attackers can supply a crafted .docx with an unterminated quoted string of repeated backslash escapes in mammoth/style-map to block the Node.js event loop.
Weakness
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Potential Mitigations
Related Attack Patterns
References
- https://github.com/mwilliamson/mammoth.js
- https://github.com/mwilliamson/mammoth.js/blob/1.12.2/lib/styles/parser/tokeniser.js#L6-L30
- https://github.com/mwilliamson/mammoth.js/commit/dc49225425c2c07de0a6dc3529f2386c82a032b4
- https://github.com/mwilliamson/mammoth.js/issues/487
- https://www.vulncheck.com/advisories/mammoth-js-1.3.0-before-1.12.3-redos-via-style-map-tokeniser