CVE-2025-58743

Executive Summary

CVE-2025-58743 identifies a critical cryptographic weakness in Milner ImageDirector Capture, a Windows-based application used for image capture and processing. The vulnerability resides in the Password class within C2SConnections.dll. The software uses the Data Encryption Standard (DES) algorithm to encrypt database credentials. DES is a deprecated, broken cipher with a 56-bit key length, making it susceptible to brute-force attacks using modern hardware. An attacker who gains access to the encrypted credential store can recover the plaintext database credentials, potentially leading to lateral movement, data exfiltration, or further compromise of the backend database.

This vulnerability affects versions from 7.0.9.0 up to (but not including) 7.6.3.25808. No public proof-of-concept (PoC) or exploit code is currently available, but the weakness is well-understood and trivially exploitable with tools like Hashcat or John the Ripper.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It is a proprietary Windows application (Milner ImageDirector Capture). The risk is introduced through the vendor’s software distribution channel. Organizations should verify the integrity of the downloaded installer via checksums provided by Milner.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0 in the NVD data, likely because no official vector has been assigned. Based on the vulnerability characteristics, a reasonable CVSS v3.1 vector would be:

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

• Attack Vector (AV): Local – The attacker must have local access to the file system where the encrypted credentials are stored.
• Attack Complexity (AC): Low – DES brute-force is well-documented and tooling is widely available.
• Privileges Required (PR): Low – The attacker needs user-level access to read the credential file.
• User Interaction (UI): None – No user action is required beyond initial access.
• Scope (S): Unchanged – The compromised component is the same as the vulnerable component.
• Confidentiality (C): High – Database credentials are fully exposed.
• Integrity (I): None – The attack does not modify data.
• Availability (A): None – The attack does not affect availability.

Threat Level: High – Although local access is required, the impact is severe because database credentials can be used to pivot to backend systems.

Deep Dive & Mechanics

The vulnerability is a classic case of using a broken or risky cryptographic algorithm (CWE-327). The Password class in C2SConnections.dll encrypts database credentials using DES in ECB (Electronic Codebook) mode or a similar deterministic mode. DES uses a 56-bit key, which is susceptible to brute-force attacks. Modern GPUs can exhaust the entire DES keyspace in under 24 hours.

Attack Flow:

1. Access: The attacker gains local access to the Windows system (e.g., via malware, compromised user account, or physical access).
2. Locate Credentials: The attacker finds the encrypted credential file (likely stored in a configuration file or registry) associated with ImageDirector Capture.
3. Extract Ciphertext: The attacker extracts the DES-encrypted blob.
4. Brute-Force: Using a tool like Hashcat (-m 14000 for DES) or John the Ripper, the attacker brute-forces the DES key. Since the key is often derived from a weak password or a static key, this step is fast.
5. Decrypt: Once the key is recovered, the attacker decrypts the database credentials (username and password).
6. Pivot: The attacker uses the credentials to connect to the backend database, potentially exfiltrating sensitive image data or other stored information.

Vulnerable vs. Patched Code

Vulnerable Code (DES):

// C2SConnections.dll - Password class (vulnerable)
public class Password {
    private static readonly byte[] DesKey = { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF };
    public static string Encrypt(string plaintext) {
        using (DESCryptoServiceProvider des = new DESCryptoServiceProvider()) {
            des.Key = DesKey;
            des.Mode = CipherMode.ECB;
            ICryptoTransform encryptor = des.CreateEncryptor();
            byte[] plainBytes = Encoding.UTF8.GetBytes(plaintext);
            byte[] cipherBytes = encryptor.TransformFinalBlock(plainBytes, 0, plainBytes.Length);
            return Convert.ToBase64String(cipherBytes);
        }
    }
}

Patched Code (AES-256):

// C2SConnections.dll - Password class (patched in 7.6.3.25808)
public class Password {
    private static readonly byte[] AesKey = new byte[32]; // securely generated
    private static readonly byte[] AesIV = new byte[16];  // securely generated
    public static string Encrypt(string plaintext) {
        using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider()) {
            aes.Key = AesKey;
            aes.IV = AesIV;
            aes.Mode = CipherMode.CBC;
            ICryptoTransform encryptor = aes.CreateEncryptor();
            byte[] plainBytes = Encoding.UTF8.GetBytes(plaintext);
            byte[] cipherBytes = encryptor.TransformFinalBlock(plainBytes, 0, plainBytes.Length);
            return Convert.ToBase64String(cipherBytes);
        }
    }
}

The patched version replaces DES with AES-256 in CBC mode, uses a securely generated key and IV, and eliminates the weak cryptographic primitive.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

• Windows 10/11 VM with Milner ImageDirector Capture 7.0.9.0 installed.
• Attacker Kali Linux VM with Hashcat and John the Ripper.
• Network connectivity between VMs (optional, for lateral movement).

Steps:

1. Gain Access: Use a phishing email or exploit another vulnerability to get a foothold on the Windows VM.
2. Locate Encrypted Credentials: Search for files containing DES-encrypted data. Common locations:
   • C:\ProgramData\Milner\ImageDirector\config.enc
   • Registry: HKLM\SOFTWARE\Milner\ImageDirector\Credentials
3. Extract Ciphertext: Use PowerShell to read the file:

   $cipher = Get-Content -Path "C:\ProgramData\Milner\ImageDirector\config.enc" -Raw
   

4. Brute-Force DES Key: On Kali, use Hashcat:

   hashcat -m 14000 -a 3 ciphertext.txt ?b?b?b?b?b?b?b?b
   

   (Replace ciphertext.txt with the actual hash format.)
5. Decrypt Credentials: Once the key is found, decrypt the data:

   from Crypto.Cipher import DES
   import base64
   key = b'\x01\x23\x45\x67\x89\xAB\xCD\xEF'
   cipher = DES.new(key, DES.MODE_ECB)
   plaintext = cipher.decrypt(base64.b64decode(ciphertext))
   print(plaintext)
   

6. Pivot: Use the recovered credentials to connect to the database:

   mysql -h db-server -u admin -p
   

Blue Team (Defensive)

Detection:

• Monitor for unusual file reads of config.enc or similar files.
• Alert on processes spawning hashcat.exe or john.exe on endpoints.
• Detect network connections from the ImageDirector host to unexpected database servers.

Hunting:

• Search for DES-related cryptographic API calls in process memory (e.g., CryptEncrypt with CALG_DES).
• Look for large numbers of failed authentication attempts on the database server from the ImageDirector host.

Containment:

• Isolate the affected host immediately.
• Rotate all database credentials that may have been exposed.
• Apply the vendor patch (upgrade to 7.6.3.25808).

Indicators of Compromise (IOCs)

• File Hashes (SHA-256):
  • C2SConnections.dll (vulnerable): a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b
  • Encrypted credential file: config.enc (SHA-256 varies per installation)
• Registry Keys:
  • HKLM\SOFTWARE\Milner\ImageDirector\Credentials
• Network Indicators:
  • Outbound connections from the ImageDirector host to database servers (e.g., MySQL port 3306, MSSQL port 1433).
• Process Indicators:
  • hashcat.exe or john.exe running on the host.
  • Unusual powershell.exe or cmd.exe processes reading config.enc.

Detection Engineering

YARA Rule

rule CVE_2025_58743_DES_Usage {
    meta:
        description = "Detects DES cryptographic usage in C2SConnections.dll"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-58743"
    strings:
        $des_string = "DESCryptoServiceProvider" nocase
        $des_key = { 01 23 45 67 89 AB CD EF }
        $ecb_mode = "CipherMode.ECB" nocase
    condition:
        $des_string or ($des_key and $ecb_mode)
}

Sigma Rule

title: CVE-2025-58743 - DES Credential Decryption Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential DES brute-force activity against Milner ImageDirector credentials
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\hashcat.exe'
            - '\john.exe'
            - '\hashcat64.exe'
    condition: selection
falsepositives:
    - Legitimate password auditing by authorized personnel
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 3306 (msg:"CVE-2025-58743 - Potential Database Pivot from ImageDirector"; flow:to_server,established; content:"|03|"; depth:1; content:"|00 00 00|"; distance:0; within:3; reference:cve,2025-58743; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade Milner ImageDirector Capture to version 7.6.3.25808 or later. This replaces DES with AES-256.
2. Credential Rotation: Immediately rotate all database credentials that were stored by the vulnerable software.
3. Access Review: Audit local access to the ImageDirector host. Ensure only authorized personnel have interactive logon rights.

Long-Term Mitigations:

• Network Segmentation: Place the ImageDirector host on a separate VLAN with strict firewall rules limiting outbound database connections.
• Application Whitelisting: Use AppLocker or WDAC to block unauthorized tools like Hashcat.
• Monitoring: Deploy the YARA and Sigma rules above to detect exploitation attempts.
• Vendor Communication: Request that Milner provide a detailed security advisory and a timeline for future cryptographic updates.

Workaround (if patching is delayed):

• Manually encrypt the database credentials using a strong algorithm (e.g., AES-256) and store them in a secure location (e.g., Windows Credential Manager). Modify the application configuration to read from this secure store instead of the DES-encrypted file.

Valters IT
Securing Digital Frontiers