This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Liquidfiles
LiquidFiles 3.4.15 has stored XSS through the "send email" functionality when sending a file via email to an administrator. When a file has no extension and contains malicious HTML / JavaScript content (such as SVG with HTML content), the payload is executed upon a click. This is fixed in 3.5. (2021-04-06, CVE-2021-30140)
An XSS issue was found in the Shares feature of LiquidFiles before 3.3.19. The issue arises from the insecure rendering of HTML files uploaded to the platform as attachments, when the -htmlview URL is directly accessed. The impact ranges from executing commands as root on the server to retrieving sensitive information about encrypted e-mails, depending on the permissions of the target user. (2020-11-25, CVE-2020-29071)
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>