CVE-2026-114398 in Trudesk
Summary
by MITRE • 10/21/2026
Trudesk through 1.2.11 contains an unrestricted file upload vulnerability that allows any authenticated user to place HTML or SVG files in the public webroot via the uploadlogo, uploadpagelogo and uploadfavicon endpoints. Attackers can spoof an image MIME type to upload script-bearing files served unauthenticated from /assets/, enabling stored cross-site scripting and replacement of instance branding.
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified in Trudesk versions through 1.2.11 represents a critical security flaw rooted in insufficient validation mechanisms within the application's file handling subsystems. Specifically, this unrestricted file upload vulnerability affects three distinct endpoints: uploadlogo, uploadpagelogo, and uploadfavicon. These endpoints are designed to allow authenticated users to customize various visual elements of the Trudesk interface by uploading image files. However, the underlying implementation fails to enforce strict constraints on the type of content being uploaded or validates the integrity of the file metadata against its actual contents. This architectural weakness permits an attacker who has obtained valid authentication credentials for a low-privilege user account to bypass standard security controls and inject malicious payloads into the server's public webroot directory, specifically within the /assets/ subdirectory where static assets are served.
The technical mechanism of exploitation relies on MIME type spoofing, a technique that exploits the discrepancy between file extensions or declared content types and their actual binary structure. An attacker can craft an HTML or SVG file but manipulate its HTTP headers to claim it is a legitimate image format such as PNG or JPEG. Because Trudesk's upload logic primarily trusts these header declarations rather than performing deep packet inspection or magic number verification, the server accepts the payload and stores it in the public directory without triggering any rejection mechanisms. Once stored, these files are served directly by the web server to clients accessing the application. Since the /assets/ directory is configured for unauthenticated access to serve static resources like logos and icons, the malicious HTML or SVG content becomes immediately accessible to any visitor of the Trudesk instance, regardless of their authentication status.
The operational impact of this vulnerability extends beyond simple data leakage, as it facilitates stored cross-site scripting attacks that can compromise the security posture of all users interacting with the affected system. By injecting script-bearing files into publicly served assets, an attacker can execute arbitrary JavaScript code in the context of other victims' browsers when they load any page that references these compromised assets. This capability allows for session hijacking, where attackers can steal authentication cookies or tokens to impersonate legitimate users and escalate privileges within the application. Furthermore, because the vulnerability affects branding elements such as logos and favicons, it enables persistent defacement of the instance's visual identity. The persistence is particularly dangerous in this context because the malicious payload remains on the server until manually removed by an administrator, meaning every user who accesses the system during that window is potentially exposed to the attack vector without any immediate indication of compromise from a UI perspective.
From a classification standpoint, this vulnerability aligns with CWE-434, which describes the unrestricted upload of files with dangerous types, and CWE-79, known as improper neutralization of input during web page generation, commonly referred to as cross-site scripting. In terms of offensive security frameworks, this exploit maps directly to MITRE ATT&CK technique T1059.007, which covers JavaScript execution within a browser environment via stored payloads. The attack path also reflects aspects of T1132, data encoding for evasion, specifically through MIME type manipulation to bypass content filters. Understanding these mappings is essential for security teams looking to detect similar patterns in their own applications or network traffic logs.
Mitigation strategies must address both the immediate risk and the underlying architectural weakness. The most effective remediation involves upgrading Trudesk to a version later than 1.2.11, where developers have presumably implemented stricter file validation logic that checks actual file content rather than relying solely on headers. For organizations unable to patch immediately due to operational constraints, several defensive measures can reduce the risk profile. Administrators should restrict write permissions for the /assets/ directory so that only specific service accounts or deployment pipelines can modify its contents, preventing authenticated application users from writing arbitrary files directly into this path if possible through configuration changes. Additionally, implementing a Web Application Firewall rule set that detects and blocks HTTP requests containing suspicious file uploads with mismatched MIME types can provide an external layer of defense. It is also advisable to configure the web server serving static assets to disable script execution within directories designated for images only, ensuring that even if malicious files are uploaded, they cannot be executed as code by client browsers. Regular auditing of uploaded files and monitoring for unusual file creation events in public-facing directories can aid in early detection of such exploitation attempts.