Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-v959-qxv6-6f8p
No affected components available
Summary
A potential vulnerability exists in ZITADEL's logout endpoint in login V2. This endpoint accepts serval parameters including a post_logout_redirect. When this parameter is specified, users will be redirected to the site that is provided via this parameter.
ZITADEL's login UI did not ensure that this parameter contained an allowed value and even executed passed scripts.
Impact
Zitadel is vulnerable to a DOM-Based XSS vulnerability. More specifically, the /logout endpoint insecurely routed to value that is supplied in the post_logout_redirect GET parameter. As a result, malicious JS code could be executed on Zitadel users’ browsers, in the Zitadel V2 Login domain.
An unauthenticated remote attacker can exploit this DOM-based XSS vulnerability, and thus, execute malicious JavaScript code on behalf of Zitadel users. By doing so, such an attacker could reset the password of their victims, and take over their accounts.
Note that for this to work, multiple user sessions need to be active in the same browser. Additionally, it's important to note that an account takeover is mitigated for accounts that have Multi-Factor Authentication (MFA) or Passwordless authentication enabled.
Affected Versions
Systems using the login UI (v2) and running one of the following versions are affected:
- v4.x:
4.0.0-rc.1through4.7.0
Patches
The vulnerability has been addressed in the latest release. The patch resolves the issue by ensuring the information was passed for the ZITADEL API using a JSON Web Token (JWT).
If you're running your own login UI, we recommend switching over to the new logout_token parameter, which contains all information previously passed via specific query parameters. The contained JWT's signature needs to be verified with the instance OAuth2/OIDC public keys (jwks_uri).
Before you upgrade, ensure that:
- the
ZITADEL_API_URLis set and is pointing to your instance, resp. system in multi-instance deployments. - the HTTP
host(or ax-forwarded-host) is passed in your reverse proxy to the login UI. - a
x-zitadel-instance-host(orx-zitadel-forward-host) is set in your reverse for multi-instance deployments. If you're running a single instance solution, you don't need to take any actions.
Patched versions:
- 4.x: Upgrade to >=4.7.1
Workarounds
The recommended solution is to update ZITADEL to a patched version.
Questions
If you have any questions or comments about this advisory, please email us at security@zitadel.com
Credits
Thanks to Amit Laish – GE Vernova for finding and reporting the vulnerability.
The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.
Exploitation activity has been observed. Apply available patches or mitigations urgently.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Browse More
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard