CVE-2021-1607 in Identity Services Engine
Summary
by MITRE • 07/09/2021
Multiple vulnerabilities in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user. These vulnerabilities exist because the web-based management interface does not sufficiently validate user-supplied input. An attacker could exploit these vulnerabilities by injecting malicious code into specific pages of the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. To exploit these vulnerabilities, the attacker would need valid administrative credentials.
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Analysis
by VulDB Data Team • 07/11/2021
The Cisco Identity Services Engine (ISE) represents a critical component in enterprise network security infrastructure, serving as a centralized policy management platform that controls network access and authentication. This vulnerability affects the web-based management interface of the ISE platform, which is commonly accessed by network administrators for configuration and monitoring purposes. The affected system operates within enterprise environments where privileged access is required to manage network security policies, making the exposure of such vulnerabilities particularly concerning for organizations relying on this platform for their security operations.
The technical flaw stems from insufficient input validation mechanisms within the web interface implementation, specifically creating conditions where stored cross-site scripting attacks can occur. This vulnerability manifests when user-supplied input is not properly sanitized or validated before being stored and subsequently rendered back to users within the interface. The weakness allows an attacker to inject malicious script code into specific pages that are then executed when other users access those pages. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79, which specifically addresses cross-site scripting flaws in web applications.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to access sensitive browser-based information and potentially escalate their privileges within the system. An authenticated attacker with administrative credentials can manipulate the interface to store malicious payloads that will execute against other administrators or users who access the compromised pages. This creates a persistent threat vector where the attacker can maintain access and potentially exfiltrate sensitive data, manipulate security policies, or establish further footholds within the network environment.
The exploitation requires an attacker to possess valid administrative credentials, which represents a baseline privilege level but also indicates that the vulnerability exists in the context of legitimate administrative access. This means that the attack vector is not purely remote but requires initial compromise of administrative credentials, potentially through phishing, credential reuse, or other attack methods. Organizations should consider implementing additional security controls such as multi-factor authentication, privileged access management solutions, and regular credential rotation to mitigate the risk associated with this vulnerability. The ATT&CK framework categorizes this vulnerability under T1078 Valid Accounts and T1566 Phishing as potential initial access methods, while the execution phase would align with T1059 Command and Scripting Interpreter.
Organizations should prioritize immediate patching of affected Cisco ISE versions, as the vulnerability affects multiple releases within the platform's lifecycle. The remediation process should include comprehensive testing of the patched environment to ensure that the input validation mechanisms have been properly implemented without introducing regressions in functionality. Network segmentation and monitoring should be enhanced to detect unusual administrative activities that might indicate exploitation attempts, particularly around the web interface access patterns. Additionally, security awareness training should be reinforced to help prevent credential compromise, as the vulnerability's exploitation requires legitimate administrative access to the system.