CVE-2025-20123: Cisco Crosswork Network Controller XSS Flaw

CVE-2025-20123 Overview

Multiple cross-site scripting (XSS) vulnerabilities have been identified in the web-based management interface of Cisco Crosswork Network Controller. These vulnerabilities allow an authenticated, remote attacker with administrative credentials to inject malicious scripts that execute in the context of other users accessing the affected interface.

The vulnerabilities stem from improper validation of user-supplied input in specific data fields within the management interface. When exploited, attackers can execute arbitrary script code in the victim's browser context or access sensitive browser-based information.

Critical Impact

Authenticated attackers can execute arbitrary JavaScript in the browsers of other administrative users, potentially leading to session hijacking, credential theft, or unauthorized configuration changes.

Affected Products

• Cisco Crosswork Network Controller (multiple versions)

Discovery Timeline

• 2025-01-08 - CVE-2025-20123 published to NVD
• 2025-07-23 - Last updated in NVD database

Technical Details for CVE-2025-20123

Vulnerability Analysis

These XSS vulnerabilities (CWE-79) exist due to insufficient input validation and output encoding in the Cisco Crosswork Network Controller's web-based management interface. The attack requires network access and valid administrative credentials, which limits the attack surface. However, the scope is changed (S:C in CVSS vector), meaning the vulnerable component impacts resources beyond its security scope—specifically, malicious scripts execute in the browsers of other authenticated users viewing the injected content.

The stored nature of these XSS flaws makes them particularly concerning in multi-administrator environments. Once malicious data is inserted into specific data fields, it persists in the application and executes whenever another administrator views the affected content. This could enable lateral movement between administrative sessions or facilitate further attacks against the network infrastructure managed by Crosswork Network Controller.

Root Cause

The root cause is improper input validation (CWE-79: Improper Neutralization of Input During Web Page Generation) in the web-based management interface. The application fails to properly sanitize and encode user-supplied input before rendering it in web pages, allowing script injection through specific data fields in the interface.

Attack Vector

The attack is network-based and requires the attacker to possess valid administrative credentials for the Cisco Crosswork Network Controller. The attack chain involves:

1. Authenticating to the web-based management interface with administrative credentials
2. Identifying vulnerable input fields that accept user data
3. Inserting malicious JavaScript or HTML content into these data fields
4. Waiting for another authenticated administrator to view the page containing the injected content
5. The malicious script executes in the victim's browser context, enabling session hijacking, data theft, or unauthorized actions

While user interaction is required (another admin must view the injected content), the attack requires low complexity once administrative access is obtained. The vulnerability allows access to sensitive browser-based information and can lead to integrity impacts through unauthorized script execution.

Detection Methods for CVE-2025-20123

Indicators of Compromise

• Unusual JavaScript or HTML tags appearing in administrative data fields within Crosswork Network Controller
• Unexpected script execution or browser behavior reported by administrators using the management interface
• Anomalous entries in application logs showing special characters or encoded script content in user input fields

Detection Strategies

• Monitor web application logs for input containing common XSS payloads such as <script>, javascript:, onerror=, or encoded variants
• Implement Content Security Policy (CSP) headers and monitor for CSP violation reports
• Review Crosswork Network Controller audit logs for suspicious data modifications in user-configurable fields
• Deploy web application firewall (WAF) rules to detect XSS injection attempts

Monitoring Recommendations

• Enable comprehensive logging for all administrative actions within Crosswork Network Controller
• Monitor for unusual session activity that may indicate session hijacking following XSS exploitation
• Implement browser-based XSS auditing and reporting mechanisms
• Review administrative user activity for unexpected changes to network configurations

How to Mitigate CVE-2025-20123

Immediate Actions Required

• Apply the software updates released by Cisco that address these vulnerabilities
• Review the Cisco Security Advisory for specific patch information and affected version details
• Audit administrative access to ensure only authorized personnel have credentials
• Implement strict access controls for the web-based management interface

Patch Information

Cisco has released software updates that address these vulnerabilities. Administrators should consult the Cisco Security Advisory (cisco-sa-xwork-xss-KCcg7WwU) for specific version information and upgrade instructions.

Workarounds

• According to Cisco, there are no workarounds that address these vulnerabilities
• Organizations should prioritize applying the official software updates
• As a defense-in-depth measure, limit administrative access to trusted networks and users while awaiting patch deployment
• Consider implementing additional network segmentation to restrict access to the management interface