Overview
This blog post details CVE-2025-20355, a medium-severity open redirect vulnerability affecting the web-based management interface of the Cisco Catalyst Center Virtual Appliance. This vulnerability could be exploited by an unauthenticated, remote attacker to redirect users to malicious web pages, potentially leading to phishing attacks or credential theft.
Technical Details
The vulnerability stems from improper input validation of HTTP request parameters within the Cisco Catalyst Center’s web interface. An attacker can exploit this by intercepting and modifying an HTTP request originating from a legitimate user. By manipulating the redirect URL parameter, the attacker can force the user’s browser to redirect to an arbitrary, attacker-controlled website after a seemingly legitimate interaction with the Catalyst Center. The lack of proper validation allows for the insertion of malicious URLs, effectively turning the trusted Catalyst Center into a vehicle for phishing or malware distribution.
CVSS Analysis
The Common Vulnerability Scoring System (CVSS) assigns CVE-2025-20355 a score of 4.7, indicating a MEDIUM severity. This score reflects the following factors:
- Attack Vector: Network (AV:N) – The vulnerability is exploitable over the network.
- Attack Complexity: High (AC:H) – Exploitation requires the attacker to intercept and modify HTTP requests, making it more challenging.
- Privileges Required: None (PR:N) – No privileges are required to exploit the vulnerability.
- User Interaction: Required (UI:R) – User interaction is required, as the attacker needs to trick the user into clicking a malicious link.
- Scope: Changed (S:C) – A successful attack can modify the security context.
- Confidentiality Impact: None (C:N)
- Integrity Impact: Low (I:L) – The attacker can modify the target’s browser to redirect to a malicious site.
- Availability Impact: None (A:N)
Possible Impact
A successful exploit of CVE-2025-20355 can have significant consequences:
- Phishing Attacks: Users could be redirected to fake login pages designed to steal their credentials for the Catalyst Center or other sensitive systems.
- Malware Distribution: Redirecting users to malicious websites can lead to the download and installation of malware, compromising their devices and potentially the entire network.
- Reputation Damage: If exploited, this vulnerability could damage the reputation of the organization using the vulnerable Cisco Catalyst Center appliance.
Mitigation and Patch Steps
To mitigate the risk posed by CVE-2025-20355, Cisco recommends upgrading your Cisco Catalyst Center Virtual Appliance to a version that includes the security fix. Please refer to the official Cisco Security Advisory for specific version information and upgrade instructions. In the meantime, consider these temporary mitigations:
- Implement Web Application Firewall (WAF) Rules: Configure your WAF to inspect HTTP request parameters for suspicious URL patterns and block requests containing potentially malicious redirects.
- Educate Users: Train users to be cautious of suspicious links and to verify the URL before entering any credentials.
- Monitor Network Traffic: Implement network monitoring to detect unusual redirect activity originating from the Catalyst Center.
