CVE-2024-4989 in API Manager
Summary
by MITRE • 10/21/2026
The callback URL parameter in WSO2 API Manager fails to validate user-supplied input, allowing it to be controlled by malicious actors.
Exploitation of this vulnerability could lead to users being redirected to attacker-controlled web pages. This can be used in conjunction with social engineering techniques to trick users into interacting with malicious links, potentially resulting in phishing attacks aimed at acquiring sensitive information or causing other harm.
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Analysis
by VulDB Data Team • 10/21/2026
The identified security flaw resides within the callback URL parameter handling mechanism of WSO2 API Manager, representing a classic instance of an Open Redirect vulnerability. This defect stems from insufficient validation and sanitization of user-supplied input directed to this specific endpoint. In secure application design, redirect targets should either be strictly whitelisted against known safe domains or undergo rigorous normalization to prevent the injection of malicious external URLs. The failure to enforce these controls allows attackers to manipulate the callback URL parameter with arbitrary values, effectively overriding the intended destination logic within the authentication and authorization flow processes managed by the platform.
From a technical perspective, this vulnerability exploits the trust relationship between the API Manager application and its users during OAuth or OIDC flows where redirect URIs are critical components. When an attacker crafts a malicious link containing their controlled domain as the callback URL, they can trick legitimate users into authenticating through WSO2 API Manager only to be immediately redirected away from the trusted environment. This mechanism bypasses standard security boundaries because the redirection is initiated by the server itself, lending an air of legitimacy to the subsequent landing page in the eyes of end-users and their browsers.
The operational impact of this vulnerability extends beyond simple navigation errors, primarily facilitating phishing campaigns and credential harvesting attacks. By leveraging social engineering techniques, malicious actors can distribute links that appear to originate from or relate directly to WSO2 API Manager services. Once a user interacts with such a link and completes any necessary authentication steps, they are seamlessly redirected to a counterfeit login page hosted by the attacker. This setup allows for the interception of sensitive credentials, session tokens, or other confidential data without triggering typical browser security warnings associated with direct navigation to untrusted sites.
This vulnerability aligns closely with CWE-601, which defines URL Redirection to Untrusted Site (Open Redirect), and is frequently utilized in conjunction with ATT&CK technique T1583.002, Acquire Infrastructure: Domains, as part of a broader attack chain aimed at establishing footholds through deception. The exploitation does not require high privileges or complex code execution; rather, it relies on the manipulation of web application logic to redirect victims, making it particularly dangerous in enterprise environments where API managers serve as central identity providers for numerous downstream services.
To mitigate this risk, immediate remediation efforts should focus on implementing strict validation rules for all callback URL parameters. Developers must enforce a whitelist approach, ensuring that only pre-approved and verified domains are accepted as valid redirect targets. Additionally, input normalization techniques can help detect attempts to bypass filters using encoded characters or alternative domain representations. Security headers such as Content-Security-Policy with appropriate frame-ancestors directives may also provide an additional layer of defense against clickjacking attacks often associated with these redirects. Regular security audits and penetration testing focused on authentication flows are recommended to identify similar weaknesses in other endpoints that handle user-controlled redirection logic within the WSO2 ecosystem.