Updraftplus Cross-site Scripting

The UpdraftPlus WordPress Backup Plugin WordPress plugin before 1.22.9 does not sanitise and escape the updraft_interval parameter before outputting it back in an admin page, leading to a Reflected Cross-Site Scripting (XSS) vulnerability. (2022-04-04, CVE-2022-0864)

The UpdraftPlus WordPress Backup Plugin WordPress plugin before 1.16.69 does not sanitise and escape the updraft_restore parameter before outputting it back in the Restore page, leading to a Reflected Cross-Site Scripting (2022-02-01, CVE-2021-25089)

The UpdraftPlus WordPress Backup Plugin WordPress plugin before 1.6.59 does not sanitise its updraft_service settings, allowing high privilege users to set malicious JavaScript payload in it and leading to a Stored Cross-Site Scripting issue (2022-01-24, CVE-2021-24423)

The UpdraftPlus WordPress Backup Plugin WordPress plugin before 1.16.66 does not sanitise and escape the backup_timestamp and job_id parameter before outputting then back in admin pages, leading to Reflected Cross-Site Scripting issues (2022-01-03, CVE-2021-25022)

Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.

The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:

https://server.com/confirmation?message=Transaction+Complete

what results in:

<span>Confirmation: Transaction Complete</span>

In that case the message can be modified to become a valid Javascript code, e.g.:

https://server.com/confirmation?message=<script>dangerous javascript code here</script>

and it will be executed locally by the user's browser with full access to the user's personal application/browser data:

<span>Confirmation: <script>dangerous javascript code here</script></span>