CVE-2017-6734 in Identity Services Engine
Summary
by MITRE
A vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) Software could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web interface of an affected device, related to the Guest Portal. More Information: CSCvd74794. Known Affected Releases: 1.3(0.909) 2.1(0.800).
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Analysis
by VulDB Data Team • 12/31/2020
The vulnerability identified as CVE-2017-6734 represents a critical cross-site scripting flaw within the web-based management interface of Cisco Identity Services Engine software versions 1.3(0.909) and 2.1(0.800). This security weakness specifically impacts the Guest Portal functionality of the ISE platform, which serves as a critical component for managing guest network access and user authentication. The vulnerability stems from inadequate input validation and output encoding mechanisms within the web interface, creating an exploitable condition that allows authenticated attackers to inject malicious scripts into web pages viewed by other users. The affected software operates within enterprise network security environments where ISE serves as a central authentication and authorization server, making this vulnerability particularly concerning for organizations relying on its guest access management capabilities.
The technical implementation of this XSS vulnerability occurs when authenticated users interact with the Guest Portal interface, which processes user inputs without proper sanitization before rendering them in web responses. This flaw enables an attacker who has already established authentication credentials to manipulate web page content through malicious script injection, potentially executing arbitrary code in the context of other users' browsers. The vulnerability manifests as a failure to properly encode or escape user-supplied data before incorporating it into dynamic web page content, which directly aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation. The attack vector requires the attacker to be authenticated to the system, but once authenticated, they can leverage this weakness to compromise other users who interact with the affected portal. This type of vulnerability falls under the ATT&CK framework's T1059.001 - Command and Scripting Interpreter: PowerShell, where the malicious script execution occurs through web-based interfaces rather than traditional command-line mechanisms.
The operational impact of CVE-2017-6734 extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal user credentials, redirect users to malicious sites, or extract sensitive information from the authenticated user's browser context. In enterprise environments where ISE manages guest access, this vulnerability could allow attackers to gain unauthorized access to guest user sessions, potentially compromising the entire guest network access control system. The vulnerability's exploitation could lead to privilege escalation within the guest portal environment, enabling attackers to manipulate guest access policies, create unauthorized guest accounts, or even gain access to administrative functions within the ISE management interface. Organizations utilizing affected ISE versions face significant risk of unauthorized access to guest network resources, which could result in data breaches, network infiltration, or disruption of legitimate guest access services.
Mitigation strategies for CVE-2017-6734 require immediate implementation of software updates from Cisco, specifically addressing the identified XSS vulnerability in the Guest Portal component of ISE software. Organizations should apply the relevant security patches and updates released by Cisco to remediate the vulnerability and ensure proper input validation and output encoding mechanisms are in place. Network administrators should also implement additional security controls such as web application firewalls that can detect and prevent XSS attacks, although these should be considered supplementary rather than primary remediation measures. Access controls should be reviewed to ensure that only authorized personnel have access to the Guest Portal functionality, and regular security audits should be conducted to identify any potential exploitation attempts. Additionally, implementing proper input validation at multiple layers of the application and network infrastructure can provide defense-in-depth against similar vulnerabilities. The vulnerability's classification as a medium severity issue in the CVSS scoring system indicates that while it may not be immediately critical, the potential for exploitation and the sensitive nature of the affected functionality warrants immediate attention and remediation to prevent potential security incidents that could impact enterprise network security posture.