CVE-2020-9322: Statamic Core XSS Vulnerability Leading to Unauthorized Admin Account Creation

Overview

In the realm of cybersecurity threats, Cross-Site Scripting (XSS) vulnerabilities remain a persistent issue. One such vulnerability, CVE-2020-9322, affects the Statamic Core before version 2.11.8. This vulnerability is of particular concern due to its high severity score and its potential to compromise systems or lead to data leakage. The vulnerability specifically targets the ‘/users’ endpoint, and its exploitation can lead to the creation of unauthorized administrator accounts, a situation that could pose significant risks to the affected systems.

Vulnerability Summary

CVE ID: CVE-2020-9322
Severity: High (8.8 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: System compromise or data leakage

Affected Products

Product | Affected Versions

Statamic Core | Before 2.11.8

How the Exploit Works

The vulnerability stems from the ‘/users’ endpoint in versions of Statamic Core before 2.11.8. An attacker can exploit this vulnerability by sending a Cross-Site Request Forgery (CSRF) attack with a JavaScript payload in a username during account registration. The payload is then stored (Stored XSS) or reflected (Reflected XSS) in the ‘/users’ PATH_INFO, leading to potential unauthorized administrative account creation or other system compromises.

Conceptual Example Code

The following is a conceptual example of what the malicious HTTP request might look like:

POST /users HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "username": "<script>malicious_code_here</script>", "password": "abc123" }

In this example, the attacker embeds a malicious script into the username field. When the system processes the request, it inadvertently executes the malicious script, potentially leading to the creation of an unauthorized administrative account or other security breaches.

Mitigation

For users affected by this vulnerability, the recommended solution is to apply the vendor patch by upgrading to Statamic Core 2.11.8 or later. As a temporary mitigation, users can also employ a Web Application Firewall (WAF) or Intrusion Detection System (IDS). These tools can help to detect and prevent the execution of malicious scripts, mitigating the risk posed by this vulnerability.