Gnuboard 5 Cross-Site Scripting Scanner

Gnuboard 5 is a widely used open-source web application framework often utilized for building community portals, websites, and forums. Developed mainly in Korea, it serves a significant number of developers looking for a customizable and robust solution for various web applications. With a focus on ease of use and flexibility, Gnuboard 5 allows users to efficiently manage and deploy extensive web systems. Its popularity has grown due to the combination of free usage and the supportive online community that frequently contributes to its development. Despite being a stable system, vulnerabilities like Cross-Site Scripting (XSS) have the potential to affect the integrity and safety of web projects built on Gnuboard 5. Hence, maintaining the security of such platforms is paramount for developers and companies relying on them.

Cross-Site Scripting (XSS) is a prevalent vulnerability found in web applications where malicious scripts are injected into otherwise benign and trusted websites. This type of vulnerability allows attackers to execute scripts in the context of the user's browser, leading to potential theft of user data, session hijacking, or defacement of the web interface. The specific XSS vulnerability in Gnuboard 5 occurs due to inadequate sanitization of user inputs by the clean_xss_tags() function called in new.php. If exploited, this vulnerability could compromise the application's security and the privacy of its users. Developing a keen understanding of how XSS works is essential for creating secure applications and protecting end-users from potential attacks.

Gnuboard 5's vulnerability lies in the handling of user inputs processed by the clean_xss_tags() function in the new.php file. The vulnerability allows attackers to craft special requests that inject script tags, such as using the darkmode parameter. This inadequacy in input sanitization results in the execution of arbitrary scripts within the user's browser context. The matching conditions, identified in the template, check for the payload in the response header and confirm a successful injection via status code 200 and specific script indicators. Understanding the exact mechanism of this vulnerability can help guide effective mitigation strategies to manage or eliminate potential exploitation.

When exploited, an XSS vulnerability in Gnuboard 5 could have several adverse effects. Attackers may steal sensitive user information such as cookies or session tokens, potentially enabling account takeovers. Additionally, they might manipulate web content or interfaces, displaying unwanted or harmful content to users. This vulnerability can also serve as a vector for further attacks, leveraging compromised user sessions for phishing or distributing malware. The reputational damage to companies using Gnuboard 5 could be significant, resulting in loss of trust among their users and decreased platform engagement. Therefore, preventing such vulnerabilities is crucial for maintaining a secure and trustworthy web application environment.

REFERENCES

• https://huntr.dev/bounties/ad2a9b32-fe6c-43e9-9b05-2c77c58dde6a/