Denial of service caused by a "heavy" regular expression

An attack where the server redirects requests to a foreign domain

Resubmitting a form when the browser reloads the page

JavaScript · Senior · Question 32 of 75

What is ReDoS?

✓Correct answer: Denial of service caused by a "heavy" regular expression
2An attack where the server redirects requests to a foreign domain
3Resubmitting a form when the browser reloads the page

Explanation

Expressions like /^(a+)+$/ on a specially crafted string take exponential time and block the thread (especially dangerous on a Node.js server). Avoid nested quantifiers, limit input length, use safe engines.

What is ReDoS?

Explanation

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