CVE-2018-17595 in Fork
Summary
by MITRE
In the 5.4.0 version of the Fork CMS software, HTML Injection and Stored XSS vulnerabilities were discovered via the /backend/ajax URI.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/20/2023
The vulnerability identified as CVE-2018-17595 affects Fork CMS version 5.4.0 and represents a critical security flaw that enables attackers to execute malicious scripts within the application's backend interface. This issue manifests through the /backend/ajax URI endpoint, which processes user input without proper sanitization or validation mechanisms. The vulnerability stems from insufficient input filtering and output encoding practices within the application's data handling pipeline, creating an environment where malicious actors can inject harmful HTML content that gets stored and subsequently executed in the context of other users' browsers.
The technical implementation of this vulnerability aligns with CWE-79 which describes Cross-Site Scripting (XSS) flaws resulting from inadequate validation of user-supplied data. Specifically, the flaw occurs in the backend AJAX processing functionality where user-provided parameters are directly incorporated into HTML responses without appropriate sanitization. This stored XSS vulnerability allows attackers to persist malicious scripts within the application's database, making the attack vector particularly dangerous as the injected content can affect multiple users who interact with the affected application components. The vulnerability operates through the standard HTTP request-response cycle where malicious input is accepted through the /backend/ajax URI and stored in the system's database.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with potential access to sensitive administrative functions and user data. When users with administrative privileges interact with the affected application components, the stored malicious scripts execute within their browser context, potentially allowing for session hijacking, privilege escalation, or data exfiltration. The stored nature of this vulnerability means that the attack persists even after the initial injection, making it particularly challenging to detect and remediate. This vulnerability directly impacts the application's integrity and confidentiality, as it enables unauthorized access to backend functionalities that should be restricted to legitimate administrators.
Security mitigations for this vulnerability should focus on implementing robust input validation and output encoding mechanisms throughout the application's data flow. The recommended approach involves applying proper HTML entity encoding to all user-supplied content before rendering it in the application interface, ensuring that any potentially malicious script content is neutralized. Additionally, implementing Content Security Policy (CSP) headers can provide an additional layer of protection against XSS attacks by restricting script execution within the browser context. The fix should also include proper parameter validation and sanitization routines specifically targeting the /backend/ajax URI endpoint to prevent any user input from being directly incorporated into HTML responses without appropriate security measures. Organizations should also implement regular security assessments and penetration testing to identify similar vulnerabilities in their web applications, following established frameworks such as the OWASP Top Ten and MITRE ATT&CK methodology for identifying and mitigating web application security risks.