CVE-2019-20437 in API Manager
Summary
by MITRE
An issue was discovered in WSO2 API Manager 2.6.0, WSO2 IS as Key Manager 5.7.0, and WSO2 Identity Server 5.8.0. When a custom claim dialect with an XSS payload is configured in the identity provider basic claim configuration, that payload gets executed, if a user picks up that dialect's URI as the provisioning claim in the advanced claim configuration of the same Identity Provider. The attacker also needs to have privileges to log in to the management console, and to add and update identity provider configurations.
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Analysis
by VulDB Data Team • 03/26/2024
This vulnerability exists in multiple WSO2 products including API Manager 2.6.0, Identity Server 5.7.0, and Identity Server 5.8.0, representing a cross-site scripting flaw that can be exploited through identity provider configuration manipulation. The vulnerability stems from improper input validation and output encoding within the identity provider claim configuration system, specifically when handling custom claim dialect URIs that contain malicious javascript payloads. The flaw manifests when an attacker configures a custom claim dialect with an XSS payload in the basic claim configuration and then references that dialect's URI in the advanced provisioning claim configuration of the same identity provider. This creates a dangerous execution path where user-supplied input flows directly into the web application's output without proper sanitization or encoding, making it susceptible to cross-site scripting attacks. The vulnerability is classified as CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a fundamental web security weakness that allows attackers to inject malicious scripts into web pages viewed by other users. The attack requires an attacker to possess valid credentials with sufficient privileges to access the management console and modify identity provider configurations, establishing a privilege escalation vector that aligns with ATT&CK technique T1078 - Valid Accounts and T1548.1 - Abuse Elevation Control Mechanism. The impact of this vulnerability extends beyond simple script execution as it can lead to session hijacking, credential theft, and potential lateral movement within the affected system. When a user accesses the management console and interacts with identity provider configurations that contain the malicious payload, the script executes in the context of the victim's browser session, potentially allowing attackers to access sensitive data, modify configurations, or perform unauthorized actions. The vulnerability represents a significant risk to organizations relying on WSO2 Identity and Access Management solutions, as it can be exploited to compromise user sessions and potentially gain deeper access to the underlying infrastructure. The exploitation requires a combination of authentication privileges and configuration manipulation capabilities, making it a medium to high severity issue that demands immediate attention from security administrators. Organizations should implement proper input validation and output encoding mechanisms to prevent such injection attacks, while also enforcing strict access controls and monitoring for unauthorized configuration changes. The vulnerability highlights the importance of secure coding practices in identity management systems and the need for comprehensive security testing of configuration management interfaces. Mitigation strategies should include immediate patching of affected versions, implementation of input validation controls, and monitoring of identity provider configuration changes to detect and prevent unauthorized modifications. The attack scenario demonstrates how seemingly benign configuration options can become attack vectors when proper security controls are not implemented, emphasizing the need for defense-in-depth approaches in identity and access management systems.