CVE-2017-6769 in Secure Access Control System
Summary
by MITRE
A vulnerability in the web-based management interface of the Cisco Secure Access Control System (ACS) could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the web interface of the affected system. More Information: CSCve70587. Known Affected Releases: 5.8(0.8) 5.8(1.5).
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Analysis
by VulDB Data Team • 01/06/2021
The vulnerability identified as CVE-2017-6769 resides within the web-based management interface of Cisco Secure Access Control System version 5.8(0.8) and 5.8(1.5), representing a critical security flaw that enables authenticated remote attackers to execute stored cross-site scripting attacks. This vulnerability specifically targets the administrative web interface of the ACS platform, which serves as the primary management portal for configuring and monitoring network access control policies. The affected system operates within enterprise environments where network security policies are centrally managed, making this vulnerability particularly concerning for organizations relying on Cisco ACS for their access control infrastructure.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the web interface components of the Cisco ACS system. When authenticated users interact with the management interface, malicious input data can be stored within the system's database or configuration parameters without proper sanitization. This stored data is subsequently served back to other authenticated users who access the same interface, creating a persistent XSS vector. The flaw allows attackers who have already established authentication credentials to inject malicious scripts that execute within the context of other legitimate users' browser sessions, potentially leading to session hijacking, privilege escalation, or data exfiltration. This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications.
The operational impact of CVE-2017-6769 extends beyond simple script execution, as it can enable attackers to manipulate the administrative interface itself and potentially gain deeper access to the underlying network infrastructure. An authenticated attacker could craft malicious payloads that, when viewed by other administrators or authorized users, would execute in their browser contexts and could be used to steal session cookies, redirect users to malicious sites, or modify configuration settings. The stored nature of this vulnerability means that the malicious input persists within the system, allowing the attack to affect multiple users over time rather than requiring continuous exploitation. This characteristic makes the vulnerability particularly dangerous in multi-user environments where administrators regularly interact with the web interface, as each user who views the affected content becomes a potential victim of the stored XSS attack.
Organizations affected by this vulnerability should implement immediate mitigations including applying the latest security patches released by Cisco, which address the input validation issues within the web interface. Network segmentation and monitoring of administrative interfaces can help detect suspicious activities that might indicate exploitation attempts. Additionally, implementing strict access controls and limiting administrative privileges to only essential personnel reduces the potential impact of successful exploitation. The vulnerability demonstrates the importance of proper input validation and output encoding in web applications, principles that align with ATT&CK technique T1059.005 for command and script injection. Security teams should also consider implementing web application firewalls and content security policies to provide additional layers of protection against similar XSS vulnerabilities in the management interfaces of network infrastructure devices.