CVE-2026-20300 in Identity Services Engine
Summary
by MITRE • 09/17/2026
A vulnerability in Cisco ISE could allow an authenticated, remote attacker to conduct SQL injection attacks on an affected device. To exploit this vulnerability, the attacker must have at least low-privileged administrative credentials.
This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to read or modify data in the underlying database.
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Analysis
by VulDB Data Team • 09/17/2026
The identified security flaw resides within Cisco Identity Services Engine, specifically affecting its handling of user-supplied input during authenticated administrative operations. This vulnerability is classified as a SQL injection issue, which stems from insufficient validation and sanitization mechanisms when processing requests directed at specific application endpoints. The technical root cause involves the failure to properly escape or parameterize data entered by users before it is incorporated into dynamic database queries. When an attacker submits crafted input containing malicious SQL syntax, the application inadvertently treats this code as part of the query structure rather than as literal data. This misinterpretation allows the injected commands to be executed directly against the underlying relational database management system that powers the ISE platform's configuration and policy storage.
Exploitation requires a significant prerequisite: the attacker must possess at least low-privileged administrative credentials on the affected device. Unlike remote code execution vulnerabilities or unauthenticated injection flaws, this threat vector is restricted to individuals who have already gained some level of access to the management interface. This constraint implies that an initial compromise of user accounts with minimal privileges is necessary before the SQL injection can be leveraged for further damage. Once authenticated, the attacker can send specially crafted HTTP requests containing malicious payloads designed to manipulate database queries. The success of such an exploit depends on the specific version and patch level of the ISE software, as well as the exact endpoint targeted within the application's API or web interface.
The operational impact of a successful exploitation is severe due to the direct access granted to the backend data store. An attacker can read sensitive information stored in the database, including user credentials, network device configurations, authentication logs, and policy definitions. This unauthorized disclosure compromises the confidentiality of critical security infrastructure data. Furthermore, the vulnerability allows for the modification or deletion of existing records within the database. By altering configuration parameters or deleting essential entries, an attacker could disrupt network access controls, bypass security policies, or cause denial-of-service conditions by corrupting the state of the identity management system. In some scenarios, depending on the specific database engine and its permissions, this level of control might even facilitate further privilege escalation to higher administrative levels or lateral movement within the network environment.
From a classification perspective, this vulnerability aligns with CWE-89, which describes Improper Neutralization of Special Elements used in an SQL Command. It also relates to ATT&CK technique T1059, specifically command and script interpretation via database commands, although it is limited by the authentication requirement. The lack of input validation represents a fundamental flaw in secure coding practices where user inputs are not treated as untrusted data until they have been rigorously sanitized or parameterized.
Mitigation strategies primarily involve applying the vendor-provided software updates that address this specific code path and enforce stricter input handling protocols. Administrators should ensure that all Cisco ISE nodes within their deployment are patched to a version where this vulnerability is resolved. In addition to patching, defense-in-depth measures such as implementing Web Application Firewalls can help detect and block SQL injection patterns in incoming traffic. Access control policies must be strictly enforced to limit administrative access only to authorized personnel with strong multi-factor authentication enabled. Regular auditing of administrative login attempts and monitoring for anomalous database query patterns can also aid in early detection of exploitation attempts, although the primary remediation remains the application of the official security patch provided by Cisco.