CVE-2024-22193

Executive Summary

CVE-2024-22193 is a vulnerability in the vantage6 platform, a technology designed to manage and deploy privacy-enhancing technologies such as Federated Learning (FL) and Multi-Party Computation (MPC). The flaw lies in the lack of input validation for encryption status when creating a task within an encrypted collaboration. A user may inadvertently submit sensitive input data that is stored unencrypted in the database, leading to a potential exposure of confidential information. The vulnerability has a CVSS score of 3.5 (Low) and is patched in version 4.2.0.

Supply Chain & Package Security

This vulnerability is specific to the vantage6 platform, which is a Python-based open-source project. The package is distributed via PyPI. Users should verify the integrity of the package by checking its checksum and ensuring it is sourced from the official PyPI repository. The patch is included in version 4.2.0, and users are strongly advised to update immediately.

CVSS Breakdown & Threat Level

• CVSS Score: 3.5 (Low)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: Low (PR:L) – An attacker needs a valid user account.
• User Interaction: Required (UI:R) – The victim must create a task with sensitive data.
• Scope: Unchanged (S:U) – The impact is confined to the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited disclosure of sensitive data.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: None (A:N) – No service disruption.

Threat Level: Low. The vulnerability requires user interaction and low privileges, but it can lead to the exposure of sensitive data if exploited.

Deep Dive & Mechanics

The vantage6 platform allows users to create tasks within collaborations that are intended to be encrypted. However, the system does not enforce encryption on the input data when a task is created. This means that if a user creates a task with sensitive input data, that data will be stored in plaintext in the database, regardless of the collaboration's encryption settings.

The root cause is the absence of a check to verify whether the input data is encrypted before storing it. This oversight can lead to accidental exposure of sensitive information, such as patient data or proprietary algorithms, if a user mistakenly assumes the data will be encrypted.

The vulnerability is present in all versions prior to 4.2.0. The patch in version 4.2.0 adds validation to ensure that input data is encrypted before storage, preventing accidental plaintext storage.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-4.2.0):

# No encryption check on input data
def create_task(data):
    # Directly store data without encryption validation
    db.store(data)

Patched Code (4.2.0+):

# Encryption check added
def create_task(data):
    if not is_encrypted(data):
        raise ValueError("Input data must be encrypted")
    db.store(data)

The patched version introduces a function is_encrypted() that validates the encryption status of the input data before storing it. This prevents accidental storage of plaintext sensitive data.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A valid user account on a vantage6 instance (version < 4.2.0).
• Access to the API endpoint for creating tasks.

Exploitation Steps:

1. Authenticate to the vantage6 API.
2. Create a task with sensitive data (e.g., patient records) without encrypting it.
3. The data is stored in plaintext in the database.
4. Retrieve the data by querying the database (if accessible) or by exploiting other vulnerabilities.

Example API Call:

curl -X POST https://vantage6.example.com/api/task \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{"data": "sensitive_patient_data"}'

Blue Team

Detection:

• Monitor API logs for tasks created without encryption headers.
• Alert on any task creation where the encrypted flag is not set to true.

Mitigation:

• Immediately upgrade to vantage6 version 4.2.0 or later.
• Implement additional monitoring to detect plaintext data storage.
• Educate users on the importance of encrypting sensitive data before submission.

Indicators of Compromise (IOCs)

• Log Entries: API logs showing task creation without encryption headers.
• Database Entries: Plaintext sensitive data stored in the task table.
• Network Traffic: Unencrypted data in API requests to /api/task endpoints.

Detection Engineering

YARA Rule

rule CVE_2024_22193_Vantage6_Unencrypted_Data
{
    meta:
        description = "Detects unencrypted sensitive data in vantage6 task creation"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-22193"
    strings:
        $sensitive = /patient|ssn|credit_card|secret/i
        $task_endpoint = "/api/task"
    condition:
        $task_endpoint and $sensitive
}

Sigma Rule

title: Vantage6 Unencrypted Task Creation
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects creation of tasks without encryption in vantage6
author: Valters IT
logsource:
    category: application
    product: vantage6
detection:
    selection:
        endpoint: "/api/task"
        encrypted: false
    condition: selection
falsepositives:
    - Legitimate unencrypted tasks (if allowed by policy)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-22193 - Vantage6 Unencrypted Task Creation";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/api/task"; http_uri;
    content:"encrypted"; http_client_body;
    pcre:"/encrypted\s*:\s*false/i";
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate Action: Upgrade to vantage6 version 4.2.0 or later.
2. Configuration: Ensure that all collaborations enforce encryption by default.
3. User Training: Educate users on the importance of encrypting sensitive data before submission.
4. Monitoring: Implement logging and alerting for unencrypted task creation.
5. Backup Review: If using an older version, review database backups for any plaintext sensitive data and remediate.

Valters IT
Securing Your Digital Frontier