CVE-2019-10170 in KeyCloak
Summary
by MITRE
A flaw was found in the Keycloak admin console, where the realm management interface permits a script to be set via the policy. This flaw allows an attacker with authenticated user and realm management permissions to configure a malicious script to trigger and execute arbitrary code with the permissions of the application user.
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Analysis
by VulDB Data Team • 10/16/2020
The vulnerability described in CVE-2019-10170 represents a critical security flaw within the Keycloak identity and access management platform, specifically affecting the admin console's realm management interface. This issue stems from insufficient input validation and sanitization mechanisms that allow authenticated users with realm management privileges to inject and execute malicious scripts within the application's policy configuration. The flaw exists in the way Keycloak handles script execution contexts within its administrative interfaces, creating a path for privilege escalation and arbitrary code execution attacks.
The technical implementation of this vulnerability involves the manipulation of the policy configuration system within Keycloak's realm management functionality. When administrators configure security policies through the console, the platform accepts script inputs without proper sanitization or validation of the script content. This design flaw enables attackers to inject malicious JavaScript or other scripting languages that get executed within the application's context. The vulnerability is particularly dangerous because it operates within the administrative interface where users already possess elevated permissions, allowing for a more severe impact than typical user-level exploits. The execution occurs with the privileges of the application user running the Keycloak service, which could potentially lead to full system compromise depending on the service account permissions.
From an operational perspective, this vulnerability creates significant risk for organizations relying on Keycloak for identity management and access control. Attackers who can authenticate as users with realm management permissions can leverage this flaw to execute arbitrary code, potentially leading to data breaches, privilege escalation, and lateral movement within the network. The impact extends beyond simple code execution as it can enable attackers to modify security policies, access sensitive user data, or even gain access to other systems that rely on Keycloak for authentication. This vulnerability directly aligns with CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and represents a classic example of a server-side code injection vulnerability that can be exploited through administrative interfaces.
The attack vector for this vulnerability requires an authenticated user with realm management permissions, making it less accessible than some other exploit scenarios but still highly concerning for organizations with compromised accounts or insider threats. The exploitation process typically involves navigating to the realm management interface, locating the policy configuration section, and injecting malicious script code that gets executed when the policy is applied or evaluated. This type of vulnerability is particularly relevant to the ATT&CK framework under the "Execution" and "Privilege Escalation" tactics, as it allows attackers to execute arbitrary code with elevated privileges and potentially move laterally within the environment. Organizations should consider implementing network segmentation, monitoring for unusual script execution patterns, and ensuring least-privilege access controls to mitigate the risk of exploitation.
Mitigation strategies for CVE-2019-10170 should focus on immediate patching of affected Keycloak versions, implementation of strict input validation and sanitization for all script inputs within administrative interfaces, and enhanced monitoring of administrative activities. Security teams should also enforce strict access controls and principle of least privilege, ensuring that only essential personnel have realm management permissions. Regular security audits of administrative interfaces and automated vulnerability scanning should be implemented to detect similar issues in other components of the identity management infrastructure. Organizations should also consider implementing web application firewalls and runtime application self-protection mechanisms to detect and prevent malicious script injection attempts. The vulnerability demonstrates the critical importance of securing administrative interfaces and validating all user inputs, particularly within systems that handle sensitive authentication and authorization functions.