CVE-2024-9679

Executive Summary

CVE-2024-9679 is a critical security vulnerability in the DLP Extension version 11.11.1.3, involving a hardcoded cryptographic key. This flaw allows an attacker with local access to decrypt previously encrypted user credentials, leading to credential theft. The vulnerability is classified under CWE-321 (Use of Hard-coded Cryptographic Key) and has a CVSS score of 5.3 (Medium). The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the impact on confidentiality is high. No public proof-of-concept (PoC) or exploit code is available at this time. The vendor has not released a patch, and the status remains UNKNOWN.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone software component (DLP Extension) used for data loss prevention.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
• Attack Vector: Local (AV:L) – The attacker must have local access to the system.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: Low (PR:L) – The attacker needs low-level privileges.
• User Interaction: None (UI:N) – No user action is required.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: High (C:H) – Encrypted credentials can be decrypted.
• Integrity Impact: None (I:N) – No data integrity is compromised.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. The vulnerability requires local access, but the impact on credential confidentiality is high. The lack of a patch increases the risk for affected systems.

Deep Dive & Mechanics

The DLP Extension 11.11.1.3 uses a hardcoded cryptographic key to encrypt user credentials. This key is embedded in the application binary or configuration files, making it accessible to anyone with local access. An attacker can extract this key and use it to decrypt the stored credentials, gaining access to sensitive data.

Technical Details:

• The encryption algorithm is likely symmetric (e.g., AES) with a static key.
• The key is stored in plaintext within the application’s code or configuration.
• The decryption process can be replicated by an attacker using the same key and algorithm.

Attack Scenario:

1. Attacker gains local access to the system (e.g., via a compromised user account).
2. Attacker locates the hardcoded key in the DLP Extension files.
3. Attacker extracts the encrypted credentials from the application’s storage.
4. Attacker uses the key to decrypt the credentials, obtaining plaintext passwords.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code remains unchanged. The following is a hypothetical example of the vulnerable code:

Vulnerable Code (Python-like pseudocode):

import base64
from Crypto.Cipher import AES

# Hardcoded key (vulnerable)
KEY = b'thisisahardcodedkey1234567890'

def encrypt_credentials(username, password):
    cipher = AES.new(KEY, AES.MODE_ECB)
    data = f"{username}:{password}".encode()
    padded_data = data + b'\x00' * (16 - len(data) % 16)
    encrypted = cipher.encrypt(padded_data)
    return base64.b64encode(encrypted)

def decrypt_credentials(encrypted_data):
    cipher = AES.new(KEY, AES.MODE_ECB)
    decrypted = cipher.decrypt(base64.b64decode(encrypted_data))
    return decrypted.rstrip(b'\x00').decode()

Patched Code (Hypothetical):

import base64
import os
from Crypto.Cipher import AES
from Crypto.Protocol.KDF import PBKDF2

# Generate a random key per installation
SALT = os.urandom(16)
KEY = PBKDF2(b'user_password', SALT, dkLen=32)

def encrypt_credentials(username, password):
    cipher = AES.new(KEY, AES.MODE_GCM)
    data = f"{username}:{password}".encode()
    ciphertext, tag = cipher.encrypt_and_digest(data)
    return base64.b64encode(cipher.nonce + tag + ciphertext)

def decrypt_credentials(encrypted_data):
    data = base64.b64decode(encrypted_data)
    nonce, tag, ciphertext = data[:16], data[16:32], data[32:]
    cipher = AES.new(KEY, AES.MODE_GCM, nonce=nonce)
    decrypted = cipher.decrypt_and_verify(ciphertext, tag)
    return decrypted.decode()

Exploitation & Lab Setup

Red Team (Attacker)

Objective: Decrypt user credentials using the hardcoded key.

Lab Setup:

• Install DLP Extension 11.11.1.3 on a test system.
• Create a user account with low privileges.
• Extract the hardcoded key from the application files (e.g., using a hex editor or strings command).

Exploitation Steps:

1. Locate the hardcoded key:

   strings /path/to/dlp_extension | grep -i "key"
   

2. Extract encrypted credentials from the application’s database or configuration file.
3. Write a decryption script using the key:

   import base64
   from Crypto.Cipher import AES
   
   KEY = b'thisisahardcodedkey1234567890'  # Extracted key
   encrypted_data = "BASE64_ENCODED_CIPHERTEXT"
   
   cipher = AES.new(KEY, AES.MODE_ECB)
   decrypted = cipher.decrypt(base64.b64decode(encrypted_data))
   print(decrypted.rstrip(b'\x00').decode())
   

4. Run the script to obtain plaintext credentials.

Blue Team (Defender)

Detection:

• Monitor for unauthorized access to DLP Extension files.
• Use file integrity monitoring (FIM) to detect changes to the application binary.
• Look for processes attempting to read the application’s configuration files.

Mitigation:

• Isolate the DLP Extension on a separate system with restricted access.
• Implement application whitelisting to prevent unauthorized scripts.
• Use credential vaults (e.g., Windows Credential Manager) instead of storing encrypted credentials locally.

Indicators of Compromise (IOCs)

• File Hashes (SHA256):
  • dlp_extension.exe: a1b2c3d4e5f6... (hypothetical)
  • config.dat: f6e5d4c3b2a1... (hypothetical)
• Registry Keys:
  • HKLM\Software\DLP Extension\EncryptionKey
• Network Indicators:
  • Unusual outbound connections from the DLP Extension process.
• Behavioral Indicators:
  • Unexpected decryption attempts on credential files.
  • Use of strings or grep on DLP Extension binaries.

Detection Engineering

YARA Rule

rule CVE_2024_9679_Hardcoded_Key {
    meta:
        description = "Detects hardcoded cryptographic key in DLP Extension 11.11.1.3"
        author = "Valters IT"
        date = "2024-10-01"
        cve = "CVE-2024-9679"
    strings:
        $key = "thisisahardcodedkey1234567890"  // Example key
        $key2 = { 74 68 69 73 69 73 61 68 61 72 64 63 6F 64 65 64 6B 65 79 31 32 33 34 35 36 37 38 39 30 } // Hex of example key
    condition:
        any of them
}

Sigma Rule

title: Detection of Hardcoded Key in DLP Extension
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to extract hardcoded cryptographic key from DLP Extension
author: Valters IT
date: 2024/10/01
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\strings.exe'
        CommandLine|contains: 'dlp_extension'
    condition: selection
falsepositives:
    - Legitimate administration
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-9679 - DLP Extension Hardcoded Key Exfiltration"; flow:to_server,established; content:"|74 68 69 73 69 73 61 68 61 72 64 63 6F 64 65 64 6B 65 79|"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate Affected Systems: Disconnect systems running DLP Extension 11.11.1.3 from the network to prevent credential exfiltration.
2. Rotate Credentials: Change all passwords and secrets that were encrypted by the vulnerable extension.
3. Apply Workaround: If possible, replace the hardcoded key with a dynamically generated key using a secure key management system.

Long-Term Fix:

• Vendor Patch: Await an official patch from the vendor that removes the hardcoded key and implements proper key management (e.g., using a hardware security module or OS-level encryption).
• Upgrade: Upgrade to a patched version once available.
• Code Review: Conduct a security audit of the application to identify other hardcoded secrets.

Compensating Controls:

• Access Control: Restrict local access to the DLP Extension installation directory.
• Monitoring: Enable logging and alerting for any attempts to read the application’s configuration files.
• Encryption: Use full-disk encryption (e.g., BitLocker) to protect data at rest.

Valters IT
Securing Digital Frontiers