CVE-2021-27884 Weak JSON Web Token in yapi-vendor

Medium 5.1 Published 1 Mar 2021 Updated 3 Aug 2024

Weak JWT secret generation allows attackers to forge tokens and take over other users' accounts in YApi.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2021-27884?

CVE-2021-27884 is a medium-severity vulnerability in n/a, published on 1 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Weak JSON Web Token (JWT) signing secret generation in YMFE YApi through 1.9.2 allows recreation of other users' JWT tokens. This occurs because Math.random in Node.js is used.

Weakness: CWE-330

Which versions are affected by CVE-2021-27884?

2 open source packages ship an affected version, including yapi-vendor. It affects 1 product.

Package	Affected	Fixed in
`yapi-vendor` npm	All versions	`1.9.3`
`yapi-vendor` npm	All versions	`1.9.3`

Products include Ymfe Yapi.

How do I fix CVE-2021-27884?

Upgrade yapi-vendor to 1.9.3 or later.

Is CVE-2021-27884 being exploited?

There is no known exploitation of CVE-2021-27884 in the wild and no public exploit code.

Sources

Also known as GHSA-2h3h-vw8r-82rp.