CVE-2024-7928: Fastadmin Path Traversal Vulnerability

CVE-2024-7928 Overview

A path traversal vulnerability has been identified in FastAdmin, a popular PHP-based backend framework. This vulnerability affects the /index/ajax/lang endpoint, where improper validation of the lang parameter allows attackers to traverse directories and potentially access sensitive files outside the intended scope.

Critical Impact

Remote attackers can exploit this path traversal flaw to read arbitrary files from the server, potentially exposing configuration files, credentials, and other sensitive data.

Affected Products

• FastAdmin versions up to and including 1.3.3.20220121

Discovery Timeline

• 2024-08-19 - CVE-2024-7928 published to NVD
• 2024-09-13 - Last updated in NVD database

Technical Details for CVE-2024-7928

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Path Traversal), where an attacker can manipulate the lang parameter in the /index/ajax/lang endpoint to escape the intended directory structure. The flaw allows the traversal of directory paths using sequences such as ../, enabling access to files and directories outside the application's designated language file directory.

The attack can be launched remotely over the network and requires low privilege access. The vulnerability primarily impacts confidentiality, allowing unauthorized disclosure of sensitive file contents. FastAdmin's language selection functionality does not properly sanitize or validate user-supplied input before using it in file path operations, creating the path traversal condition.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the language parameter handling functionality. The application fails to properly sanitize the lang argument before constructing file paths, allowing directory traversal sequences to be processed and executed. This enables attackers to break out of the intended language file directory and access arbitrary files on the system.

Attack Vector

The vulnerability is exploited through network-based requests to the /index/ajax/lang endpoint. An attacker with low-level privileges can craft malicious requests containing path traversal sequences in the lang parameter. The attack does not require user interaction and can be automated for exploitation at scale.

By manipulating the lang parameter with directory traversal sequences (e.g., ../../../etc/passwd), an attacker can read sensitive system files or application configuration files that may contain database credentials, API keys, or other sensitive information.

Detection Methods for CVE-2024-7928

Indicators of Compromise

• HTTP requests to /index/ajax/lang containing path traversal sequences such as ../, ..%2f, or URL-encoded variants
• Unusual access patterns to the language endpoint with non-standard parameter values
• Web server logs showing attempts to access files outside the language directory structure

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block path traversal patterns in the lang parameter
• Monitor HTTP request logs for requests to /index/ajax/lang containing suspicious characters or encoded traversal sequences
• Deploy intrusion detection systems (IDS) with signatures for path traversal attack patterns
• Review access logs for unusual file read operations outside normal application directories

Monitoring Recommendations

• Enable verbose logging on the FastAdmin application to capture all requests to the /index/ajax/lang endpoint
• Configure alerts for any requests containing path traversal indicators targeting FastAdmin endpoints
• Implement file integrity monitoring on sensitive configuration files to detect unauthorized access attempts

How to Mitigate CVE-2024-7928

Immediate Actions Required

• Upgrade FastAdmin to version 1.3.4.20220530 or later immediately
• Review web server access logs for evidence of exploitation attempts
• Audit any sensitive files that may have been exposed through this vulnerability
• Change credentials for any systems that may have been compromised through file disclosure

Patch Information

The vendor has addressed this vulnerability in FastAdmin version 1.3.4.20220530. Upgrading to this version or later will remediate the path traversal vulnerability in the /index/ajax/lang endpoint. Additional technical details about this vulnerability are available in the VulDB Advisory and the Shikangsi Wiki Post.

Workarounds

• Implement input validation at the web server or reverse proxy level to reject requests containing path traversal sequences
• Restrict access to the /index/ajax/lang endpoint using firewall rules or access control lists until patching is complete
• Deploy a WAF rule to block requests with ../ patterns in the lang parameter

# Example nginx configuration to block path traversal attempts
location /index/ajax/lang {
    if ($arg_lang ~* "\.\./") {
        return 403;
    }
}