Description
Mailvelope prior to 3.1.0 is vulnerable to a clickjacking attack against the settings page. As the settings page is intended to be accessible from web applications, the browser's extension isolation mechanisms are disabled (web_accessible_resources). Mailvelope implements additional measures to prevent web applications from directly embedding the settings page, but this mechanism can be bypassed.
References
- https://github.com/mailvelope/mailvelope/blob/master/Changelog.md#v310
- https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Publications/Studies/Mailvelope_Extensions/Mailvelope_Extensions_pdf.html
- https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Publications/Studies/Mailvelope_Extensions/Mailvelope_Extensions_pdf.pdf?__blob=publicationFile&v=3