This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in All In One Seo Pack
An issue was discovered in the All in One SEO Pack plugin before 3.6.2 for WordPress. The SEO Description and Title fields are vulnerable to unsanitized input from a Contributor, leading to stored XSS. (2021-01-01, CVE-2020-35946)
The all-in-one-seo-pack plugin before 3.2.7 for WordPress (aka All in One SEO Pack) is susceptible to Stored XSS due to improper encoding of the SEO-specific description for posts provided by the plugin via unsafe placeholder replacement. (2019-10-16, CVE-2019-16520)
Why Cross-site Scripting can be dangerous
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>