In September 2022, a Cross-Site Scripting (XSS) vulnerability was found in one of the most popular SharePoint workflow tools — Nintex Workflow Plugin version 5.2.2.30. Known as CVE-2022-38167, this flaw could have allowed attackers to inject malicious code into SharePoint environments, targeting both users and administrators.

This post breaks down what happened, shows a basic proof-of-concept, and shares ways you can keep your systems safe. I’ll use simple language and stick to the facts.

What is Nintex Workflow Plugin?

Many organizations use SharePoint for collaboration and document management. Nintex Workflow makes automation easy: you can build forms, approvals, and processes without writing a single line of code.

Workflows are powerful — but if the workflow plugin is vulnerable, the entire SharePoint environment is at risk. That’s exactly what went wrong with version 5.2.2.30.

What is CVE-2022-38167?

CVE-2022-38167 is a vulnerability in Nintex Workflow’s handling of user-supplied data. It’s a reflected Cross-Site Scripting (XSS) bug. In simple terms: if a bad guy tricks a user into clicking a specially crafted SharePoint link, arbitrary JavaScript code runs in their browser, with their permissions.

XSS explained

XSS means an attacker can inject and execute JavaScript on web pages viewed by other users. This script can steal cookies, capture login credentials, or perform actions on behalf of the user.

Where was the bug?

The vulnerable component was found in the way Nintex processed certain parameters in workflow URLs and possibly inside *workflow comments*. Lack of input validation meant user input was not properly sanitized.

How did an attacker exploit it?

An attacker could send a specially crafted link to a fellow employee or post it somewhere public like a SharePoint discussion thread. When the victim clicked, malicious code was executed in their browser.

Let’s say your company SharePoint URL is

https://sharepoint.example.com/sites/hr/Workflows/NintexWorkflow.aspx?ListId=abc123&ItemId=1

The vulnerable parameter was ItemId (and possibly others). The attacker could use this

https://sharepoint.example.com/sites/hr/Workflows/NintexWorkflow.aspx?ListId=abc123&ItemId=1%3Cscript%3Ealert(1)%3C/script%3E

If you clicked on this, you would suddenly see a pop-up

!js-alert

That means arbitrary JavaScript is being executed. Replace alert(1) with serious code, and an attacker could:

Let’s sketch the possible buggy code

string itemId = Request.QueryString["ItemId"];
// Vulnerable line -- unsanitized output
Response.Write("<input type='hidden' value='" + itemId + "'>");

Fix: Use proper encoding/sanitization

string itemId = HttpUtility.HtmlEncode(Request.QueryString["ItemId"]);
Response.Write("<input type='hidden' value='" + itemId + "'>");

Who Published This Vulnerability?

A security researcher going by RyotaK reported it responsibly. The vulnerability was disclosed on September 9, 2022.

- NVD details: CVE-2022-38167
- Exploit entry on Packet Storm

How to Stay Safe

Nintex released a patched version after learning about this flaw. If you manage a SharePoint environment:

Update Nintex Workflow to the latest release.

2. Regularly check security advisories from Nintex.
3. Monitor your SharePoint instance for suspicious activity/logins.

Conclusion

XSS bugs are among the most common, but also the most dangerous security bugs, especially inside business tools like SharePoint. CVE-2022-38167 is a clear reminder to always treat user input as dangerous.

If your company uses Nintex Workflow and you haven’t updated past 5.2.2.30, you are vulnerable. Take action today.

References

- CVE-2022-38167 at NIST NVD
- Packet Storm: Nintex Workflow 5.2.2.30 XSS
- Nintex Product Security Updates

Timeline

Published on: 11/14/2022 21:15:00 UTC
Last modified on: 11/17/2022 20:25:00 UTC