CVE-2026-54380 in VitaFit
Summary
by MITRE • 11/05/2026
VitaFit cloud API before 2026-10-30 contained a stored cross-site scripting vulnerability that allows authenticated attackers to upload an SVG image containing malicious JavaScript to the shared storage bucket. Attackers can exploit the application's failure to restrict scripts or force downloads for image/svg+xml content, causing the JavaScript to execute when a victim opens the file via direct browser navigation.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability identified in VitaFit cloud API prior to version 2026-10-30 represents a critical security flaw classified as Stored Cross-Site Scripting, commonly referred to as persistent XSS. This type of vulnerability is particularly dangerous because the malicious payload is stored on the target server rather than being delivered via a one-time link. In this specific instance, the application fails to adequately sanitize or validate user-supplied input when handling file uploads, specifically allowing attackers to upload Scalable Vector Graphics files that contain embedded JavaScript code. The core technical failure lies in the application's content type handling logic, which does not enforce strict restrictions on scripts within image/svg+xml MIME types nor does it force a download of such files instead of rendering them directly in the browser context.
From an operational perspective, this flaw allows authenticated attackers to bypass standard security controls by leveraging the trust relationship between the user and the application. Once an attacker successfully uploads an SVG file containing malicious JavaScript to the shared storage bucket, the payload becomes persistent within the system environment. When a victim user navigates directly to view or interact with this stored file through their web browser, the browser interprets the content as executable code rather than static image data. This results in the immediate execution of the attacker's script within the security context of the authenticated session, effectively granting the adversary control over the victim's interaction with the application without requiring further social engineering tactics beyond initial access to upload functionality.
The impact of this vulnerability extends significantly beyond simple defacement or alert boxes. Because the JavaScript executes in the context of an authenticated user session, attackers can perform a wide range of malicious actions including stealing sensitive cookies and session tokens, performing unauthorized state-changing requests on behalf of the victim, capturing keystrokes, or redirecting users to phishing sites. This capability undermines the confidentiality, integrity, and availability principles that underpin secure software design. The use of SVG files is particularly insidious because many web applications treat images as safe binary data, leading developers to overlook the potential for script injection within XML-based image formats like SVG which support embedded scripting elements such as `<script>` tags or event handlers like `onload`.
This vulnerability aligns with CWE-79, Improper Neutralization of Input During Web Page Generation known as Cross-site Scripting, and more specifically reflects issues related to improper validation of file types and content. In the context of the MITRE ATT&CK framework, this exploitation technique maps to techniques involving client-side code injection and potentially credential harvesting through session hijacking if cookies are accessible via JavaScript. The failure to enforce Content Security Policy headers or implement strict MIME type sniffing restrictions contributes directly to the exploitability of this flaw.
To mitigate this vulnerability, developers must implement rigorous input validation on all file upload endpoints. This includes verifying that uploaded files match expected content types using both extension checks and deep inspection of file signatures rather than relying solely on client-side hints or HTTP headers. For SVG files specifically, it is essential to strip out any executable elements such as script tags, event handlers, and external entity references before storing the file in shared storage. Additionally, implementing a Content Security Policy that restricts inline scripts and enforces strict MIME type sniffing can significantly reduce the impact of successful injection attempts. Setting appropriate HTTP headers such as X-Content-Type-Options: nosniff ensures browsers respect the declared content type and do not attempt to mime-sniff files into executable contexts. Finally, applying output encoding when displaying user-supplied data in web pages remains a fundamental defense-in-depth strategy against cross-site scripting attacks.