Permissive Cross-domain Policy with Untrusted Domains Affecting com.vaadin:vaadin package, versions [14.14.0,14.14.8)[23.6.0,23.6.17)[24.4.0,24.4.26)[24.5.0,24.7.17)[24.8.0,24.9.24)[24.10.0,24.10.12)[25.0.0,25.2.11)[25.3.0,25.3.3)

com.vaadin:vaadin is a Java framework for modern Java web applications.

Affected versions of this package are vulnerable to Permissive Cross-domain Policy with Untrusted Domains via the push endpoint reflecting the request Origin into the Access-Control-Allow-Origin response header and allowing credentials. An attacker can access sensitive information by making cross-origin requests with the user's cookies and reading the response. This is only exploitable if the application uses server push and the attacker knows the push identifier of the session.

This vulnerability can be mitigated by setting the servlet init parameter org.atmosphere.cpr.dropAccessControlAllowOriginHeader to true on the Vaadin servlet, which stops the header being emitted without upgrading. In a Spring Boot application, the Vaadin servlet must be registered explicitly for the parameter to be applied.

• GitHub Issue
• GitHub PR
• Vaadin Advisory