graphql-scalars PhoneNumber scalar is vulnerable to regular expression denial of service

Summary

The regular expression behind GraphQLPhoneNumber since 1.24.1 backtracks exponentially. A string made of a run of digits followed by one character that makes the match fail (for example "1".repeat(30) + "x") blocks the JavaScript thread for seconds, and every additional digit doubles the time.

graphql-js calls parseLiteral while validating a document and parseValue while coercing variables, so the regex runs for every request that merely contains such a value in a PhoneNumber position, before execution and before any authentication or authorization step of the server. One small unauthenticated request is enough to stall a server process.

Affected versions

• graphql-scalars >= 1.24.1,