Source: cna@vuldb.com
A vulnerability has been found in EmpireSoft EmpireCMS up to 8.0. Impacted is the function CheckSaveTranFiletype of the file e/class/connect.php. Such manipulation leads to unrestricted upload. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
EmpireCMS versions up to 8.0 are vulnerable to unrestricted file upload due to a flaw in the CheckSaveTranFiletype function within `e/class/connect.php**. This allows attackers to upload malicious files, potentially leading to remote code execution and complete system compromise.
Step 1: Target Identification: Identify a vulnerable EmpireCMS installation (version <= 8.0).
Step 2: Payload Preparation: Craft a malicious file (e.g., a PHP web shell) with a file extension that bypasses the validation checks (e.g., a double extension like .php.jpg or a crafted content-type header).
Step 3: Exploit Trigger: Locate the file upload functionality within EmpireCMS, likely related to image uploads, document uploads, or other file-handling features.
Step 4: File Upload: Upload the crafted malicious file through the identified upload mechanism.
Step 5: File Placement: The upload bypasses the validation and the file is uploaded to a publicly accessible directory.
Step 6: Remote Code Execution: Access the uploaded malicious file via a web browser, triggering the execution of the malicious code and granting the attacker control over the server.
The vulnerability stems from a flawed implementation of file type validation in the CheckSaveTranFiletype function. The function likely fails to adequately sanitize or validate the file extension or content type of uploaded files. This allows an attacker to bypass the intended security checks and upload files with malicious content, such as web shells or executable scripts. The lack of vendor response further exacerbates the risk, as no official patches or mitigations are available.
While no specific APTs are directly linked to this CVE, the ease of exploitation and potential for complete system compromise makes it attractive to various threat actors, including those seeking to establish a foothold for further attacks (e.g., ransomware deployment, data exfiltration). This vulnerability is a high-risk target. CISA KEV status: Likely to be added soon.
Monitor web server access logs for unusual file uploads, especially files with suspicious extensions or file names.
Analyze network traffic for POST requests containing file uploads to the EmpireCMS installation.
Implement file integrity monitoring to detect unauthorized file modifications within the web server's document root.
Examine web server access logs for requests to suspicious files, such as those with unusual extensions or file names.
Use a web application firewall (WAF) to detect and block malicious file uploads based on file type, content, and headers.
Implement a robust file type validation mechanism that verifies both the file extension and the content type of uploaded files. Use a whitelist approach, allowing only explicitly permitted file types.
Ensure that uploaded files are stored outside of the web server's document root or in a directory with restricted execution permissions.
Regularly update EmpireCMS to the latest version, even if no official patch is available. Implement a WAF to mitigate the vulnerability.
Review and harden the web server configuration, including disabling unnecessary modules and features.
Implement a web application firewall (WAF) with rules specifically designed to detect and block malicious file uploads.