CVE-2026-20175 in Finesse
Summary
by MITRE • 06/03/2026
A vulnerability in Cisco Finesse could allow an unauthenticated, remote attacker to load arbitrary files from remote locations into an active user session on an affected device, possibly leading to browser-based attacks.
This vulnerability is due to insufficient validation of user-supplied input for HTTP requests that are sent to an affected device. An attacker who has knowledge of the address of the affected device could exploit this vulnerability by persuading a user to click a crafted link that contains the affected device address. A successful exploit could allow the attacker to conduct browser-based attacks and execute arbitrary script code in the context of the affected interface or access sensitive information on the affected device.
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Analysis
by VulDB Data Team • 06/03/2026
This vulnerability in Cisco Finesse represents a critical security flaw that enables unauthenticated remote attackers to perform arbitrary file loading attacks against active user sessions. The vulnerability stems from inadequate input validation mechanisms within the HTTP request processing pipeline of the affected device. Security researchers have identified this issue as a significant risk to organizations relying on Cisco Finesse for their customer relationship management operations. The flaw specifically manifests when the system fails to properly validate user-supplied input in HTTP requests, creating an attack surface that can be exploited without authentication credentials. This vulnerability is particularly dangerous because it operates entirely within the browser context of active user sessions, allowing attackers to execute malicious code directly within the targeted environment.
The technical implementation of this vulnerability follows a classic browser-based attack pattern that leverages cross-site scripting and file inclusion techniques. The insufficient input validation creates a condition where malicious HTTP requests can be processed without proper sanitization of user-provided parameters. Attackers can craft malicious links that, when clicked by a legitimate user, trigger the vulnerability and establish a remote execution channel. This type of attack falls under the CWE-20 category of "Improper Input Validation" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript" as it enables the execution of arbitrary script code within the browser context. The vulnerability's exploitation requires minimal attacker privileges since no authentication is needed, making it particularly attractive for automated attack campaigns.
The operational impact of this vulnerability extends beyond simple code execution to encompass comprehensive session hijacking and data exfiltration capabilities. When successfully exploited, attackers can execute arbitrary script code in the context of the affected interface, potentially gaining access to sensitive information stored within the Finesse environment. This includes customer data, session tokens, and other confidential information that organizations rely on for business operations. The attack vector specifically targets active user sessions, meaning that any legitimate user who clicks the malicious link becomes compromised. Organizations using Cisco Finesse for call center operations face particular risk since these systems often contain highly sensitive customer information, making the potential data breach impact significantly higher than typical web application vulnerabilities.
Mitigation strategies for this vulnerability should focus on immediate implementation of input validation controls and network-level protections. Organizations should implement web application firewalls to filter suspicious HTTP requests and restrict access to the affected device through network segmentation. The Cisco advisory recommends updating to the latest software versions that contain patches for this vulnerability, which typically include enhanced input validation mechanisms and improved request parsing. Network administrators should also consider implementing strict access controls that limit the exposure of Finesse interfaces to untrusted networks and require multi-factor authentication for administrative access. Additionally, user education programs should be established to raise awareness about phishing attacks and suspicious links that could be used to exploit this vulnerability, as social engineering remains a primary attack vector for this type of flaw. The implementation of Content Security Policies and strict browser security controls can further reduce the attack surface and limit the potential impact of successful exploitation attempts.