EspoCRM is a free, open-source customer relationship management platform. Prior to version 9.0.8, HTML Injection in Knowledge Base (KB) articles leads to complete page defacement imitating the login page. Authenticated users with the read knowledge article privilege can browse to the KB article and if they submit their credentials, they get captured in plain text. The vulnerability is allowed by overly permissive HTML editing being allowed on the KB articles. Any authenticated user with the privilege to read KB articles is impacted. In an enterprise with multiple applications, the malicious KB article could be edited to match the login pages of other applications, which would make it useful for credential harvesting against other applications as well. Version 9.0.8 contains a patch for the issue.
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.