CVE-2026-20285 in Identity Services Engine Software
Summary
by MITRE • 09/16/2026
A vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC) could allow an authenticated, remote attacker to modify parts of the configuration on an affected device.
This vulnerability is due to the lack of server-side validation of Administrator permissions. An attacker could exploit this vulnerability by submitting a crafted HTTP request to an affected system. A successful exploit could allow the attacker to modify descriptions of files on a specific page. To exploit this vulnerability, an attacker would need valid Administrator credentials.
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Analysis
by VulDB Data Team • 09/16/2026
The identified security flaw resides within the web-based management interface of Cisco Identity Services Engine and its Passive Identity Connector component, presenting a significant risk to organizations relying on these platforms for network access control and policy enforcement. The core technical deficiency is a failure in server-side validation regarding Administrator permissions during specific configuration modification operations. While the system correctly authenticates users based on provided credentials, it fails to rigorously verify that the authenticated session possesses the requisite privilege level before processing requests intended to alter administrative settings. This architectural oversight allows an attacker who has obtained valid Administrator-level credentials to bypass expected access controls by submitting crafted HTTP requests that manipulate internal state without proper authorization checks at the application logic layer.
From a technical perspective, this vulnerability is classified as an insecure direct object reference or broken access control issue where the server trusts client-supplied data regarding user roles rather than validating them against its own authoritative security context. An attacker exploiting this flaw would need to first compromise or obtain legitimate Administrator credentials through phishing, credential stuffing, or other initial access vectors. Once authenticated, the attacker can craft specific HTTP requests targeting endpoints responsible for modifying file descriptions and configuration parameters on affected pages. The exploit relies on manipulating these inputs to alter system configurations in ways that were not intended by the security model, effectively bypassing granular permission checks that should have restricted such actions to only those users with explicit administrative rights designated for those specific tasks.
The operational impact of this vulnerability is substantial because it undermines the integrity and confidentiality guarantees provided by Cisco ISE. By allowing an authenticated user to modify configuration details, including file descriptions and potentially other underlying settings depending on the exact endpoint behavior, an attacker can disrupt service availability, hide malicious activities from audit logs, or create backdoors for persistent access. Although the immediate exploit described involves modifying descriptions of files, such actions often serve as a precursor to more severe attacks where attackers might alter policy definitions, disable security features, or redirect authentication flows to exfiltrate sensitive network data. The requirement for valid Administrator credentials means that this is not an unauthenticated remote code execution risk but rather a privilege abuse scenario that highlights the danger of over-provisioned accounts and insufficient separation of duties within administrative interfaces.
To mitigate this vulnerability, organizations must ensure they are running software versions where Cisco has implemented strict server-side validation checks to verify user permissions before processing configuration changes. Immediate remediation involves applying the latest security patches released by Cisco for both Identity Services Engine and Passive Identity Connector components. In addition to patching, administrators should enforce strict access control policies by limiting the number of users with full Administrator privileges and implementing role-based access control where possible to ensure that only necessary personnel have elevated rights. Multi-factor authentication should be enabled for all administrative accounts to reduce the risk of credential compromise, and network segmentation should restrict management plane traffic to trusted networks only. Regular auditing of administrative actions and monitoring for anomalous HTTP request patterns can also help detect potential exploitation attempts before significant damage occurs. This issue aligns with CWE-269 Improper Privilege Management and is relevant to MITRE ATT&CK techniques involving Account Manipulation and Defense Evasion, emphasizing the need for robust identity governance in critical infrastructure components.