Impact Luxon's DateTime.fromRFC2822() has quadratic (N^2) complexity on some specific inputs. This causes a noticeable slowdown for inputs with lengths above 10k characters. Users providing untrusted data to this method are therefore vulnerable to (Re)DoS attacks.

This is the same bug as Moment's https://github.com/moment/moment/security/advisories/GHSA-wc69-rhjr-hc9g

Workarounds Limit the length of the input.

References There is an excellent writeup of the same issue in Moment: https://github.com/moment/moment/pull/6015#issuecomment-1152961973

Details DateTime.fromRFC2822("(".repeat(500000)) takes a couple minutes to complete.

Impact

using string-to-date parsing in moment (more specifically rfc2822 parsing, which is tried by default) has quadratic (N^2) complexity on specific inputs noticeable slowdown is observed with inputs above 10k characters users who pass user-provided strings without sanity length checks to moment constructor are vulnerable to (Re)DoS attacks

Patches The problem is patched in 2.29.4, the patch can be applied to all affected versions with minimal tweaking.

Workarounds In general, given the proliferation of ReDoS attacks, it makes sense to limit the length of the user input to something sane, like 200 characters or less. I haven't seen legitimate cases of date-time strings longer than that, so all moment users who do pass a user-originating string to constructor are encouraged to apply such a rudimentary filter, that would help with this but also most future ReDoS vulnerabilities.

References There is an excellent writeup of the issue here: https://github.com/moment/moment/pull/6015#issuecomment-1152961973=

Details The issue is rooted in the code that removes legacy comments (stuff inside parenthesis) from strings during rfc2822 parsing. moment("(".repeat(500000)) will take a few minutes to process, which is unacceptable.

Impact This vulnerability impacts npm (server) users of moment.js, especially if user provided locale string, eg fr is directly used to switch moment locale.

Patches This problem is patched in 2.29.2, and the patch can be applied to all affected versions (from 1.0.1 up until 2.29.1, inclusive).

Workarounds Sanitize user-provided locale name before passing it to moment.js.

References Are there any links users can visit to find out more?

For more information If you have any questions or comments about this advisory: Open an issue in moment repo

Node.js moment module is vulnerable to a denial of service. A remote attacker could exploit this vulnerability to cause a low severity regular expression denial of service.

moment is vulnerable to regular expression denial of service when user input is passed unchecked into moment.duration() blocking the event loop for a period of time.

Upstream patch:

https://github.com/moment/moment/pull/2939

External References:

https://nodesecurity.io/advisories/55