CVE-2025-7066 in Jirafeau
Summary
by MITRE • 07/04/2025
Jirafeau normally prevents browser preview for text files due to the possibility that for example SVG and HTML documents could be exploited for cross site scripting. This was done by storing the MIME type of a file and allowing only browser preview for MIME types beginning with image (except for image/svg+xml, see CVE-2022-30110 and CVE-2024-12326), video and audio. However, it was possible to bypass this check by sending a manipulated MIME type containing a comma and an other MIME type like text/html (for example image/png,text/html). Browsers see multiple MIME types and text/html would takes precedence, allowing a possible attacker to do a cross-site scripting attack. The check for MIME types was enhanced to prevent a browser preview when the stored MIME type contains a comma.
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Analysis
by VulDB Data Team • 08/14/2025
CVE-2025-7066 represents a critical server-side request forgery vulnerability in Jirafeau, a web-based file sharing application designed to facilitate secure file transfers while mitigating cross-site scripting risks. The vulnerability stems from an insufficient MIME type validation mechanism that was intended to prevent browser preview of potentially dangerous file types such as HTML and SVG documents. This security control was implemented by maintaining a stored MIME type value and only permitting browser preview for files with MIME types beginning with image, video, or audio prefixes, with specific exceptions for image/svg+xml files to address previous vulnerabilities. However, the implementation contained a fundamental flaw that allowed threat actors to bypass this protective mechanism through a carefully crafted MIME type manipulation technique.
The technical exploitation of this vulnerability relies on the HTTP Content-Type header manipulation where attackers can submit a malformed MIME type value containing a comma delimiter followed by a malicious MIME type such as text/html. This technique exploits how web browsers process multiple MIME type declarations in a single Content-Type header, where the browser typically prioritizes the first MIME type in the list for rendering purposes. When Jirafeau processes a file with a comma-delimited MIME type like "image/png,text/html", the system stores this composite value but fails to properly validate the entire string against its security policy. The browser then interprets the composite MIME type and renders the content based on the first type while the application's validation logic only examines the initial portion, allowing malicious HTML content to bypass the intended security controls.
This vulnerability directly maps to CWE-20: Improper Input Validation and CWE-79: Cross-Site Scripting, as it demonstrates both inadequate validation of user-supplied data and the potential for executing malicious scripts in victim browsers. The attack vector aligns with ATT&CK technique T1203: Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code through browser-based interfaces. The operational impact of this vulnerability is significant as it undermines the core security premise of Jirafeau's file preview protection mechanism, potentially allowing attackers to inject malicious scripts into HTML documents that would otherwise be restricted. When a victim accesses a file containing malicious JavaScript within a preview context, the script executes in the victim's browser with the privileges of the Jirafeau application, enabling potential data theft, session hijacking, or further attack propagation.
The mitigation strategy for CVE-2025-7066 requires implementing a comprehensive MIME type validation approach that thoroughly examines the entire stored MIME type value rather than relying on prefix-based checks alone. System administrators should update Jirafeau to the latest patched version that enforces strict MIME type validation by rejecting any stored MIME types containing comma delimiters or other potentially malicious formatting patterns. Additionally, organizations should implement additional layers of protection including Content Security Policy headers, strict MIME type enforcement at the web server level, and regular security auditing of file upload and preview mechanisms. Network monitoring should be enhanced to detect suspicious MIME type patterns and abnormal file access behaviors, while application-level logging should track all MIME type validation attempts and bypass events to support forensic analysis and incident response activities.