CVE-2021-32702 Reflected XSS from the callback handler's error query parameter
Attackers can execute arbitrary JavaScript via reflected XSS in the callback error parameter, affecting Next.js applications using the Auth0 SDK.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-32702?
CVE-2021-32702 is a high-severity cross-site scripting vulnerability in nextjs-auth0, published on 25 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. Versions before and including `1.4.1` are vulnerable to reflected XSS. An attacker can execute arbitrary code by providing an XSS payload in the `error` query parameter which is then processed by the callback handler as an error message. You are affected by this vulnerability if you are using `@auth0/nextjs-auth0` version `1.4.1` or lower **unless** you are using custom error handling that does not return the error message in an HTML response. Upgrade to version `1.4.1` to resolve. The fix adds basic HTML escaping to the error message and it should not impact your users.
Weakness: CWE-79
Which versions are affected by CVE-2021-32702?
2 open source packages ship an affected version, including @auth0/nextjs-auth0. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@auth0/nextjs-auth0 npm | All versions | 1.4.2 |
@auth0/nextjs-auth0 npm | All versions | 1.4.2 |
Products include Auth0 Nextjs-Auth0.
How do I fix CVE-2021-32702?
Upgrade @auth0/nextjs-auth0 to 1.4.2 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-32702 being exploited?
There is no known exploitation of CVE-2021-32702 in the wild and no public exploit code.
Other vulnerabilities in nextjs-auth0
Sources
Also known as GHSA-954c-jjx6-cxv7.