Threats tagged 'ghsa-r8f2-fxjr-gx5r'

Umbraco CMS versions prior to 17.7.2 and 18.2.2 have an authentication bypass vulnerability. This flaw allows unauthenticated attackers to register malicious OAuth redirect URIs by manipulating the Host header. Attackers can then trick signed-in users into using authorization links with response_mode=form_post to capture authorization codes. These codes can be redeemed using HTTP Basic client credentials to hijack back-office sessions and execute arbitrary code via Razor templates.