In February 2022, Microsoft patched a notable vulnerability, tracked as CVE-2022-24472, affecting several versions of SharePoint Server. Discovered and responsibly disclosed, this weakness attracted attention due to its potential to allow attackers to spoof content—and possibly trick your users or escalate an attack. This post offers an exclusive and straightforward breakdown: what CVE-2022-24472 is, why it matters, how the exploit works, and what you need to know as a SharePoint administrator or security pro.

What is CVE-2022-24472?

CVE-2022-24472 is a spoofing vulnerability found in Microsoft SharePoint Server. Spoofing vulnerabilities let attackers make something look like it comes from a trusted source when it doesn’t. In this case, the bug lets someone create links or responses that appear to come from SharePoint but actually originate from somewhere else, which could trick users or other systems.

Microsoft SharePoint Server 2019

For a full product list, check Microsoft’s Security Guide.

Making malicious requests look like they come from your organization

If you have users who trust SharePoint links or interface, a spoofed response can easily bypass their suspicions.

Under the Hood: How the Exploit Works

Microsoft’s official write-up is concise and does not disclose technical details, but researchers and community posts have shared insights. Here’s a simplified outline of the exploitation process.

The Problem:
SharePoint poorly validated certain user-supplied input when generating or returning URLs. An attacker could provide a crafted URL or parameter that would:

Trick the browser or the user into thinking this response truly comes from SharePoint.

This often involves open redirection or response manipulation.

Code Snippet Example

Here’s a simplified conceptual code snippet illustrating what might go wrong in a typical vulnerable SharePoint handler:

// Example pseudocode for dangerous behavior
string redirectUrl = Request.QueryString["redirect"];
if (!string.IsNullOrEmpty(redirectUrl))
{
    Response.Redirect(redirectUrl); // Bad: does not validate target!
}

In the context of SharePoint, a crafted request like

https://sharepoint.yoursite.com/_layouts/15/redirect.aspx?redirect=http://evil.com/

could cause users clicking SharePoint links (or receiving links from an attacker) to be silently redirected outside your trusted domain—even though the URL started at your SharePoint address!

Exploit Details: Proof-of-Concept (PoC)

While Microsoft has not published a public PoC, and ethical security demands discretion, the "recipe" is well-understood:

Craft a URL embedding an external or specially-formatted address in the parameter.

3. Send the link to your target (user/social engineering, or automated browser/user).
4. Result: The link appears to be safe and from SharePoint, but actually delivers the target to the attacker’s infrastructure or causes a script to execute.

Simplified Demo

Suppose your SharePoint instance is at https://intranet.corp.com/.

Send a coworker

https://intranet.corp.com/_layouts/15/redirect.aspx?redirect=http://badguy.com/

If unpatched, clicking this link would redirect the user to badguy.com, even though the address bar started with your company’s main SharePoint URL.

Real-World Impact

This bug relies on abuse of trust. Many employees and admins trust anything hosted at their SharePoint server’s address. A successful attacker could:

How to Fix: Patch It!

Good News:
Microsoft released updates as a part of their February 2022 Patch Tuesday.

Install the security updates for your version of SharePoint.

- Microsoft’s official advisory: CVE-2022-24472 | SharePoint Server Spoofing Vulnerability

Use built-in SharePoint URL encoding and validation methods.

- Train users to be cautious about email or chat links, even if they look like they come from inside the organization.

Resources & References

- Microsoft Official Advisory — CVE-2022-24472
- NVD Entry — CVE-2022-24472
- Patch Tuesday February 2022 Summary
- SharePoint Security Best Practices — Microsoft Docs

Summary

CVE-2022-24472 is a reminder that even mature, enterprise products like SharePoint can have simple but dangerous bugs. Spoofing vulnerabilities open doors for bigger attacks, and attackers are always looking for new footholds. As always, stay patched, stay alert, and help your users understand the risks of trusting every link in their inbox.

If your SharePoint Server is public, patch now. If it’s internal, still patch now. Don’t let spoofing be the start of a breach at your workplace.


*Exclusive breakdown by [Your Name / Site], June 2024. Please share responsibly.*

Timeline

Published on: 04/15/2022 19:15:00 UTC
Last modified on: 04/22/2022 01:37:00 UTC