CVE-2024-4040 in CrushFTP
Summary
by MITRE • 04/22/2024
A server side template injection vulnerability in CrushFTP in all versions before 10.7.1 and 11.1.0 on all platforms allows unauthenticated remote attackers to read files from the filesystem outside of the VFS Sandbox, bypass authentication to gain administrative access, and perform remote code execution on the server.
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Analysis
by VulDB Data Team • 01/28/2025
This vulnerability represents a critical server-side template injection flaw in CrushFTP software that affects versions prior to 10.7.1 and 11.1.0 across all platforms. The vulnerability stems from improper input validation and sanitization within the template processing engine, allowing attackers to inject malicious template code that gets executed on the server. The flaw exists in the way the application handles user-supplied data during template rendering processes, creating an attack vector that bypasses normal security controls.
The technical exploitation of this vulnerability enables unauthenticated remote attackers to perform multiple malicious activities through a single entry point. Attackers can leverage the template injection to read arbitrary files from the server filesystem outside of the Virtual File System sandbox, potentially accessing sensitive configuration files, user credentials, or system information. The vulnerability also permits bypassing authentication mechanisms, allowing attackers to escalate privileges and gain administrative access to the FTP server. This privilege escalation capability combined with the file reading functionality creates a comprehensive attack chain that can lead to full system compromise.
The operational impact of this vulnerability is severe and multifaceted, affecting organizations that rely on CrushFTP for file transfer services. The ability to execute remote code on the server means attackers can establish persistent backdoors, exfiltrate data, or deploy additional malware. The vulnerability's unauthenticated nature makes it particularly dangerous as it requires no prior access credentials to exploit, turning any network-connected CrushFTP server into a potential target. Organizations may experience complete loss of data integrity and confidentiality, with potential regulatory compliance violations due to unauthorized access to sensitive information.
Mitigation strategies should prioritize immediate patching of affected systems to version 10.7.1 or 11.1.0, which contain the necessary fixes for the template injection vulnerability. Network segmentation and firewall rules should be implemented to restrict access to FTP services, limiting exposure to unauthorized networks. Input validation and sanitization should be enhanced throughout the application, particularly in template processing components. The principle of least privilege should be enforced by running the FTP service with minimal required permissions and implementing proper access controls. Security monitoring should be enhanced to detect unusual file access patterns or template processing activities that might indicate exploitation attempts. This vulnerability aligns with CWE-74 and CWE-94 categories related to template injection and code injection respectively, and maps to ATT&CK techniques including T1059 for command and script injection and T1078 for valid accounts exploitation. Organizations should conduct thorough security assessments of their FTP infrastructure and implement comprehensive monitoring solutions to detect potential exploitation attempts.