HexBrain

Nextcloud · Report #952349

Possible denial of service when entering a loooong password

Validstatus
mediumseverity
16upvotes
16 Sept 2020disclosed

How it was found

You can create a very long password until you get the last user to put and aries or [DoS]. *Normally passwords have 8-10-24 digits. By sending a very long password (1.000.000 characters) Usually this problem is caused by a vulnerable password hashing implementation. When a long password is sent, the password hashing process will result in CPU and memory exhaustion.

**Remediation The password hashing implementation must be fixed to limit the maximum length of accepted passwords.

**step to reproduce:- 1.go to the link https://demo2.nextcloud.com/index.php/login 2.Try to log in to any account you want there

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Impact

it's possible to cause a denial a service attack on the server. This may lead to the website becoming unavailable or unresponsive.

This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original