CVE-2020-15084 Authorization bypass in express-jwt
Attackers can bypass authorization in express-jwt if algorithms are not configured, allowing unauthorized access to protected resources.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2020-15084?
CVE-2020-15084 is a high-severity authentication bypass vulnerability in auth0 express-jwt, published on 30 Jun 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
In express-jwt (NPM package) up and including version 5.3.3, the algorithms entry to be specified in the configuration is not being enforced. When algorithms is not specified in the configuration, with the combination of jwks-rsa, it may lead to authorization bypass. You are affected by this vulnerability if all of the following conditions apply: - You are using express-jwt - You do not have **algorithms** configured in your express-jwt configuration. - You are using libraries such as jwks-rsa as the **secret**. You can fix this by specifying **algorithms** in the express-jwt configuration. See linked GHSA for example. This is also fixed in version 6.0.0.
Which versions are affected by CVE-2020-15084?
2 open source packages ship an affected version, including express-jwt. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
express-jwt npm | All versions | 6.0.0 |
express-jwt npm | All versions | 6.0.0 |
Products include Auth0 Express-Jwt.
How do I fix CVE-2020-15084?
Upgrade express-jwt to 6.0.0 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2020-15084 being exploited?
There is no known exploitation of CVE-2020-15084 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1774570939, CLSA-2026-1774570940, GHSA-6g6m-m6h5-w9gf, ROOT-APP-NPM-CVE-2020-15084.