Advisories for Golang/Github.com/Zitadel/Zitadel package

2025

IDOR Vulnerabilities in ZITADEL's Admin API that Primarily Impact LDAP Configurations

ZITADEL's Admin API contains Insecure Direct Object Reference (IDOR) vulnerabilities that allow authenticated users, without specific IAM roles, to modify sensitive settings. While several endpoints are affected, the most critical vulnerability lies in the ability to manipulate LDAP configurations. Customers who do not utilize LDAP for authentication are not at risk from the most severe aspects of this vulnerability. However, we still strongly recommend upgrading to the patched version to …

IDOR Vulnerabilities in ZITADEL's Admin API that Primarily Impact LDAP Configurations

ZITADEL's Admin API contains Insecure Direct Object Reference (IDOR) vulnerabilities that allow authenticated users, without specific IAM roles, to modify sensitive settings. While several endpoints are affected, the most critical vulnerability lies in the ability to manipulate LDAP configurations. Customers who do not utilize LDAP for authentication are not at risk from the most severe aspects of this vulnerability. However, we still strongly recommend upgrading to the patched version to …

2024

User Registration Bypass in Zitadel

Zitadel allows administrators to disable the user self-registration. Due to a missing security check in versions prior to 2.63.4, disabling the "User Registration allowed" option only hid the registration button on the login page. Users could bypass this restriction by directly accessing the registration URL (/ui/login/loginname) and register a user that way.

Denied Host Validation Bypass in Zitadel Actions

A flaw in the URL validation mechanism of Zitadel actions allows bypassing restrictions intended to block requests to localhost (127.0.0.1). The isHostBlocked check, designed to prevent such requests, can be circumvented by creating a DNS record that resolves to 127.0.0.1. This enables actions to send requests to localhost despite the intended security measures.

ZITADEL has improper HTML sanitization in emails and Console UI

ZITADEL uses HTML for emails and renders certain information such as usernames dynamically. That information can be entered by users or administrators. Due to a missing output sanitization, these emails could include malicious code. This may potentially lead to a threat where an attacker, without privileges, could send out altered notifications that are part of the registration processes. An attacker could create a malicious link, where the injected code would …

ZITADEL "ignoring unknown usernames" vulnerability

ZITADEL administrators can enable a setting called "Ignoring unknown usernames" which helps mitigate attacks that try to guess/enumerate usernames. If enabled, ZITADEL will show the password prompt even if the user doesn't exist and report "Username or Password invalid". Due to a implementation change to prevent deadlocks calling the database, the flag would not be correctly respected in all cases and an attacker would gain information if an account exist …

ZITADEL Vulnerable to Session Information Leakage

ZITADEL provides users the ability to list all user sessions of the current user agent (browser) by API and in the Console UI. Due to a missing check, user sessions without that information (e.g. when created though the session service) were incorrectly listed exposing potentially other user's sessions. Note that the Login UI was never affected and there was no possibility to take over such a session.

ZITADEL's Improper Content-Type Validation Leads to Account Takeover via Stored XSS + CSP Bypass

ZITADEL users can upload their own avatar image and various image types are allowed. Due to a missing check, an attacker could upload HTML and pretend it is an image to gain access to the victim's account in certain scenarios. A possible victim would need to directly open the supposed image in the browser, where a session in ZITADEL needs to be active for this exploit to work. The exploit …

ZITADEL's actions can overload reserved claims

Under certain circumstances an action could set reserved claims managed by ZITADEL. For example it would be possible to set the claim urn:zitadel:iam:user:resourceowner:name {"urn:zitadel:iam:user:resourceowner:name": "ACME"} if it was not set by ZITADEL itself. To compensate for this we introduced a protection that does prevent actions from changing claims that start with urn:zitadel:iam

Improper HTML sanitization in ZITADEL

ZITADEL uses Go templates to render the login UI. Due to a improper use of the text/template instead of the html/template package, the Login UI did not sanitize input parameters. An attacker could create a malicious link, where he injected code which would be rendered as part of the login screen. While it was possible to inject HTML including javascript, the execution of such scripts would be prevented by the …

Account Takeover via Session Fixation in Zitadel [Bypassing MFA]

ZITADEL uses a cookie to identify the user agent (browser) and its user sessions. Although the cookie was handled according to best practices, it was accessible on subdomains of the ZITADEL instance. An attacker could take advantage of this and provide a malicious link hosted on the subdomain to the user to gain access to the victim’s account in certain scenarios. A possible victim would need to login through the …

2023

ZITADEL Account Takeover via Malicious Host Header Injection

Impact ZITADEL uses the notification triggering requests Forwarded or X-Forwarded-Host header to build the button link sent in emails for confirming a password reset with the emailed code. If this header is overwritten and a user clicks the link to a malicious site in the email, the secret code can be retrieved and used to reset the users password and take over his account. Accounts with MFA or Passwordless enabled …

ZITADEL race condition in lockout policy execution

ZITADEL provides identity infrastructure. ZITADEL provides administrators the possibility to define a Lockout Policy with a maximum amount of failed password check attempts. On every failed password check, the amount of failed checks is compared against the configured maximum. Exceeding the limit, will lock the user and prevent further authentication. In the affected implementation it was possible for an attacker to start multiple parallel password checks, giving him the possibility …

Weak Password Recovery Mechanism for Forgotten Password

ZITADEL provides identity infrastructure. In versions 2.37.2 and prior, ZITADEL administrators can enable a setting called "Ignoring unknown usernames" which helps mitigate attacks that try to guess/enumerate usernames. While this settings was properly working during the authentication process it does not work correctly on the password reset flow. This meant that even if this feature was active that an attacker could use the password reset function to verify if an …

Insufficient Session Expiration

ZITADEL is a combination of Auth0 and Keycloak. RefreshTokens is an OAuth 2.0 feature that allows applications to retrieve new access tokens and refresh the user's session without the need for interacting with a UI. RefreshTokens were not invalidated when a user was locked or deactivated. The deactivated or locked user was able to obtain a valid access token only through a refresh token grant. When the locked or deactivated …

2022