CVE-2019-20439 in API Manager
Summary
by MITRE
An issue was discovered in WSO2 API Manager 2.6.0. A potential Reflected Cross-Site Scripting (XSS) vulnerability has been identified in defining a scope in the "manage the API" page of the API Publisher.
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Analysis
by VulDB Data Team • 03/26/2024
The vulnerability identified in CVE-2019-20439 represents a critical security flaw within the WSO2 API Manager 2.6.0 platform, specifically affecting the API Publisher component's scope management functionality. This issue manifests as a reflected cross-site scripting vulnerability that occurs when users define scopes within the "manage the API" page interface. The vulnerability stems from inadequate input validation and output encoding mechanisms within the web application's user interface, creating an avenue for malicious actors to inject malicious script code into the application's response.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious payload containing script code and injects it into the scope definition parameters within the API Publisher's management interface. When the application processes this input and reflects it back to the user's browser without proper sanitization, the malicious script executes in the context of the victim's session. This creates a persistent threat vector where attackers can manipulate the application's behavior, potentially stealing session cookies, performing unauthorized actions, or redirecting users to malicious websites. The vulnerability specifically impacts the scope definition functionality, which is a core administrative feature used to control access permissions for API resources within the WSO2 platform.
The operational impact of this reflected XSS vulnerability extends beyond simple script execution, as it can enable attackers to escalate privileges within the API Manager environment. An attacker who successfully exploits this vulnerability could gain unauthorized access to sensitive API management functions, potentially compromising the entire API ecosystem managed by WSO2. The attack surface is particularly concerning given that the vulnerability exists in the API Publisher's administrative interface, which typically requires elevated privileges to access. This means that successful exploitation could lead to complete compromise of the API management infrastructure, allowing attackers to modify API configurations, manipulate access controls, and potentially access sensitive data processed through the API gateway.
Mitigation strategies for this vulnerability should prioritize immediate patching of the WSO2 API Manager to version 2.6.1 or later, which includes the necessary security fixes. Organizations should implement comprehensive input validation mechanisms that sanitize all user-supplied data before processing, particularly focusing on the scope definition parameters within the API Publisher interface. The implementation of proper output encoding techniques ensures that any potentially malicious content is rendered harmless when displayed to users. Additionally, organizations should deploy web application firewalls and security monitoring tools to detect and prevent exploitation attempts. The vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for script injection, highlighting the need for robust application security controls. Security teams should also conduct regular security assessments of the API Manager environment to identify similar vulnerabilities in other components and ensure that all administrative interfaces properly validate and sanitize user input to prevent similar exploitation vectors.