Description

The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.

Weaknesses 1

Affected Products 3

References 6

• github.com https://github.com/zitadel/zitadel/commit/7abe759c95cb360524d88b51744d03cbb6e4dcdb
  Patch
• github.com https://github.com/zitadel/zitadel/releases/tag/v2.71.15
  Release Notes
• github.com https://github.com/zitadel/zitadel/releases/tag/v3.4.0
  Release Notes
• github.com https://github.com/zitadel/zitadel/releases/tag/v4.0.3
  Release Notes
• github.com https://github.com/zitadel/zitadel/security/advisories/GHSA-g9c3-xh6v-fr86
  Vendor Advisory
• zitadel.com https://zitadel.com/docs/self-hosting/manage/production#limits-and-quotas
  Product

Remediation

• github.com https://github.com/zitadel/zitadel/commit/7abe759c95cb360524d88b51744d03cbb6e4dcdb
  Patch