CVE-2022-42149 Scanner

kkFileView is a server-side file viewing application used to render and view files directly over a web interface. It is commonly employed by companies and individuals who need to provide online previews of documents and files without requiring local software installations on client machines. The tool supports a range of document types making it versatile for multi-format document handling. In organizational settings, it helps decrease dependency on client-side software while optimizing document management workflows. With its wide usage and access features, kkFileView enhances file-sharing capabilities among team members. Its intuitive interface allows even non-technical users to easily manage and share files securely.

Server-Side Request Forgery (SSRF) is a vulnerability that allows attackers to induce the server to make arbitrary requests. Such vulnerabilities can exploit a server's functionality by sending crafted requests to internal resources that otherwise would be inaccessible. Attackers leverage these requests to exfiltrate information, access sensitive data, or interact with other components within the server. The SSRF vulnerability in kkFileView owes its existence due to improper validation in the OnlinePreviewController.java file. This defect can be exploited without requiring authentication from the user, posing a significant risk. Understanding and mitigating this vulnerability is critical for maintaining the security posture of affected systems.

The vulnerability in kkFileView lies in the OnlinePreviewController.java file where improper input validation allows attackers to craft requests that facilitate SSRF. The vulnerable endpoint `/onlinePreview?url=` accepts a parameter which is base64 encoded and has potential to trigger dangerous backend requests if manipulated. By decoding inputs improperly validated, an attacker can make the server access arbitrary URLs. Such unauthorized external requests could lead to data leaks or interactions with unauthorized resources. The server's capacity to decode and process these crafted URLs is at the heart of this vulnerability. Mitigations involve ensuring robust input validation and restrictions for sensitive resources.

Exploiting this SSRF vulnerability could have severe implications for an organization. Attackers might access sensitive data or underlying services with elevated privileges. Such access can lead to information leakage where private data or configurations get exposed inadvertently. In worse scenarios, it may offer attackers a pivot point to conduct further attacks within the internal network including accessing restricted segments or attacking other services. The organization's reputation and functionality can take a hit if critical operations are disrupted as a consequence of such exploits.

REFERENCES

• https://github.com/kekingcn/kkFileView/issues/296
• https://nvd.nist.gov/vuln/detail/CVE-2022-42149