WSO2 Server-Side Request Forgery Scanner

WSO2 is an open-source technology provider offering various software products used across enterprises globally. It is commonly deployed for managing APIs, applications, and identity management solutions, often leveraged by developers and IT teams to facilitate seamless integrations within their architecture. The software allows organizations to connect and manage enterprise, mobile, IoT apps and APIs across cloud and on-premise environments. Its robust applications are utilized to support digital transformation initiatives worldwide. With its comprehensive features, WSO2 targets industries like finance, healthcare, and government, enhancing services integration and process optimization. Garnishing a broad user base, it caters to extensive enterprise-scale applications needing flexible and scalable solutions.

Server-Side Request Forgery (SSRF) is a vulnerability in which an attacker can make the server-side application initiate requests to unintended resources. In this specific case, WSO2 versions before 5.8.0 are susceptible, allowing unauthorized queries to internal systems or third-party services. The vulnerability is particularly attributed to the misuse of UI gadgets in the shindig web application. Exploiting this flaw could potentially lead to malicious actors fetching sensitive data or executing malicious actions. It poses a risk due to its capability to alter server requests without proper validation mechanisms in place. Efficiently detecting and mitigating this vulnerability is essential to avoiding potential compromise.

Technically, this SSRF vulnerability arises from improper handling of URL entries within WSO2's gadget proxy service. The vulnerable endpoint is exposed at `/shindig/gadgets/proxy` where a parameter titled `url` can be tampered with. This allows the attacker to specify arbitrary URLs, forcing WSO2 to perform HTTP requests to these destinations. Critical parameters have not been sufficiently sanitized or verified, exposing the system's backend to unauthorized access. This, coupled with the attacker-controlled URL, significantly broadens the attack surface, facilitating both internal and external scanning from within the server. Detection hinges on identifying such crafted requests through known patterns and defensive practices.

Exploitation of the SSRF vulnerability could result in exposure of internal endpoints and resources, effectively bypassing firewall protections. Attackers may leverage this for recon, such as discovering open ports or services in otherwise inaccessible systems. It can also lead to unauthorized access to internal resources like metadata services, potentially resulting in data breaches. Moreover, such vulnerabilities may serve as a pivot point for further attacks, escalating into more severe consequences like data manipulation or unauthorized service interactions. Addressing SSRF helps in fortifying perimeter defenses against such unauthorized manipulations from server-side perspectives.

REFERENCES

• https://docs.wso2.com/display/Security/Security+Advisory+WSO2-2019-0598