CVE-2019-10169 in KeyCloak
Summary
by MITRE
A flaw was found in Keycloak’s user-managed access interface, where it would permit a script to be set in the UMA policy. This flaw allows an authenticated attacker with UMA permissions to configure a malicious script to trigger and execute arbitrary code with the permissions of the user running application.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/16/2020
The vulnerability identified as CVE-2019-10169 represents a critical security flaw within Keycloak's User-Managed Access (UMA) framework that fundamentally undermines the system's security model. This issue exists in the user-managed access interface where the system fails to properly validate or sanitize script inputs, creating an avenue for privilege escalation and arbitrary code execution. The flaw specifically affects the UMA policy configuration mechanism, which is designed to allow users to define access policies for their resources, but inadvertently permits the injection of malicious scripts that can be executed within the application's context.
This vulnerability operates through a code injection attack vector that aligns with CWE-94, which describes the improper execution of code due to insufficient input validation. The technical flaw manifests when an authenticated attacker with UMA permissions can manipulate the policy configuration to include malicious script content that gets executed by the application. The security implications are severe because the executed code runs with the privileges of the user who configured the policy, potentially allowing attackers to escalate their privileges or access sensitive data within the application's operational scope.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to leverage the authenticated user's permissions to perform actions that would otherwise be restricted. This creates a significant risk for organizations relying on Keycloak for identity and access management, as the vulnerability can be exploited to gain unauthorized access to protected resources, manipulate access controls, or potentially move laterally within the system. The attack requires only authentication and existing UMA permissions, making it particularly dangerous as it can be exploited by insiders or compromised users with appropriate access levels.
Organizations should implement immediate mitigations including comprehensive input validation for all UMA policy configurations, strict sanitization of script inputs, and enhanced monitoring of policy changes. The vulnerability demonstrates the importance of following secure coding practices and input validation as outlined in the OWASP Top 10 security principles. Security teams should also consider implementing network segmentation and privilege separation to limit the potential impact of such vulnerabilities. Additionally, regular security assessments and penetration testing should be conducted to identify similar injection flaws in other components of the Keycloak ecosystem, as this vulnerability type represents a common pattern in identity management systems that require careful validation of user-supplied content to prevent unauthorized code execution.