CVE-2024-42054 in Cervantes
Summary
by MITRE • 07/28/2024
Cervantes through 0.5-alpha accepts insecure file uploads.
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Analysis
by VulDB Data Team • 08/17/2026
The vulnerability identified in Cervantes versions up to and including the 0.5-alpha release pertains to an insecure direct object reference or improper validation mechanism within its file upload functionality. This flaw allows unauthenticated or authenticated attackers, depending on the specific deployment configuration, to bypass intended access controls and upload arbitrary files to the server hosting the application. The core technical deficiency lies in the absence of rigorous input sanitization and type checking for uploaded content. Instead of validating that incoming files conform to expected formats such as images or documents based on their MIME types or magic numbers, the system likely relies solely on client-side validation or a simplistic extension-based check which can be trivially circumvented using standard web proxy tools like Burp Suite or OWASP ZAP. This lack of server-side enforcement creates a critical security gap where malicious payloads disguised as benign file extensions are accepted and stored in accessible directories.
The operational impact of this vulnerability is severe, particularly if the uploaded files are executed by the underlying web server or application logic. An attacker can exploit this flaw to upload a Web Shell, which serves as a persistent backdoor into the compromised system. Once the shell is uploaded and accessed via its URL, it grants the attacker interactive command-line access to the operating system running Cervantes. This effectively results in full remote code execution (RCE), allowing the adversary to exfiltrate sensitive data, modify application configurations, install additional malware such as rootkits or cryptominers, or use the compromised server as a pivot point for further attacks against internal network resources. The severity is amplified if the web service runs with elevated privileges, potentially leading to complete system compromise and loss of confidentiality, integrity, and availability.
This vulnerability aligns closely with CWE-434, which describes the unrestricted upload of files with dangerous types, as well as CWE-20 for improper input validation where the application fails to sufficiently verify that incoming data meets specified requirements before processing it. From a tactical perspective within the MITRE ATT&CK framework, this flaw facilitates initial access through web applications and enables command and control operations via uploaded scripts or shells. The exploitation path typically involves crafting a malicious file with an allowed extension but containing executable code in its header or body, then submitting it through the upload interface provided by Cervantes.
Mitigation strategies must focus on implementing robust server-side validation mechanisms immediately upon upgrading to a patched version if available. If no patch exists for the 0.5-alpha release, administrators should disable file uploads entirely unless strictly required for business operations. When uploads are necessary, developers must implement strict allow-lists for permitted file extensions and MIME types rather than relying on deny lists which can be bypassed through encoding tricks or double extension attacks. Additionally, uploaded files should be stored in a directory that is not executable by the web server, ensuring that even if a malicious script is uploaded, it cannot be directly executed via HTTP requests. Renaming uploaded files to random strings upon storage further mitigates the risk of direct access. Implementing Content Security Policy headers and using antivirus scanning on upload endpoints can provide additional layers of defense against this class of vulnerability.