RE2JS is the JavaScript port of RE2, a regular expression engine that provides linear time matching. From 2.2.0 until 2.8.7, enabling LOOKBEHINDS and using repeated matching through matcher().find(), matchAll(), split(), or matcher().replaceAll() can cause quadratic total work. Machine.match restarts lookbehind scanning from offset zero for each requested start position, while Matcher-based APIs request capture slots that prevent the early exit used for captureless matching. Dense matches therefore repeatedly rescan the input, allowing attacker-influenced text to monopolize a single-threaded worker and deny service. This issue is fixed in version 2.8.7.
Weakness
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
References
- https://github.com/le0pard/re2js/commit/dfdd947785dfa113bdc97416375c246a39458395
- https://github.com/le0pard/re2js/pull/59
- https://github.com/le0pard/re2js/releases/tag/2.8.7
- https://github.com/le0pard/re2js/security/advisories/GHSA-gg6h-894w-4m9c
- https://github.com/le0pard/re2js/security/advisories/GHSA-gg6h-894w-4m9c