Envira Gallery Cross-site Scripting

The Gallery Plugin for WordPress plugin before 1.8.4.7 does not escape the $_SERVER['REQUEST_URI'] parameter before outputting it back in an attribute, which could lead to Reflected Cross-Site Scripting in old web browsers (2022-10-31, CVE-2022-2190)

Unvalidated input and lack of output encoding in the Envira Gallery Lite WordPress plugin, versions before 1.8.3.3, did not properly sanitise the images metadata (namely title) before outputting them in the generated gallery, which could lead to privilege escalation. (2021-03-18, CVE-2021-24126)

A stored cross-site scripting (XSS) issue in Envira Gallery Lite before 1.8.3.3 allows remote attackers to inject arbitrary JavaScript/HTML code via a POST /wp-admin/admin-ajax.php request with the meta[title] parameter. (2021-01-15, CVE-2020-35581)

A stored cross-site scripting (XSS) issue in Envira Gallery Lite before 1.8.3.3 allows remote attackers to inject arbitrary JavaScript/HTML code via a POST /wp-admin/post.php request with the post_title parameter. (2021-01-15, CVE-2020-35582)

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>