CVE-2025-31283

Executive Summary

CVE-2025-31283 is a broken access control vulnerability in Trend Vision One’s User Roles component. An authenticated administrator could create users who could then modify their own role assignments, leading to privilege escalation. The vulnerability has been remediated on the backend service and is no longer considered active. The CVSS score is 4.6 (Medium), with a low EPSS probability (0.0%), indicating minimal exploitation risk. No public proof-of-concept code or exploit templates are available.

Supply Chain & Package Security

This vulnerability is not related to any open-source package (NPM, PyPI, Go, Ruby). It affects a proprietary SaaS component of Trend Vision One. No supply chain implications exist.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
• Base Score: 4.6 (Medium)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: High (administrator)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Medium. The vulnerability requires administrative access to exploit, limiting the attack surface. The backend fix has been applied, and no active exploitation has been observed.

Deep Dive & Mechanics

The vulnerability resides in the User Roles component of Trend Vision One, a cloud-based security platform. The component manages role-based access control (RBAC) for users. A flaw in the access control logic allowed an administrator to create new users without proper validation of role assignment permissions. Once created, these users could modify their own role to a higher privilege level (e.g., from a standard user to an administrator), effectively bypassing intended restrictions.

Root Cause: The backend service did not enforce proper authorization checks when creating users or when users attempted to update their own roles. The system relied on client-side or insufficient server-side validation, enabling privilege escalation.

Attack Flow:

1. An authenticated administrator creates a new user account via the User Roles API.
2. The new user logs in and sends a request to change their role (e.g., from "User" to "Admin").
3. The backend processes the request without verifying that the user has permission to modify their own role.
4. The user gains elevated privileges, potentially accessing sensitive data or performing administrative actions.

Impact: An attacker with administrative access could create backdoor accounts with escalated privileges, leading to unauthorized data access, configuration changes, or lateral movement within the Trend Vision One environment.

Vulnerable vs. Patched Code

No specific code snippets are available as this is a proprietary SaaS product. However, the vulnerability can be described conceptually:

Vulnerable Logic (Conceptual):

// Backend API endpoint for creating users
app.post('/api/users/create', (req, res) => {
  // No check if the requester has permission to create users with specific roles
  const newUser = createUser(req.body.username, req.body.role);
  res.status(201).json(newUser);
});

// Backend API endpoint for updating user role
app.put('/api/users/:id/role', (req, res) => {
  // No check if the user can modify their own role
  updateUserRole(req.params.id, req.body.newRole);
  res.status(200).json({ success: true });
});

Patched Logic (Conceptual):

// Backend API endpoint for creating users
app.post('/api/users/create', (req, res) => {
  // Verify that the requester has admin privileges and can assign roles
  if (!isAdmin(req.user) || !canAssignRole(req.user, req.body.role)) {
    return res.status(403).json({ error: 'Forbidden' });
  }
  const newUser = createUser(req.body.username, req.body.role);
  res.status(201).json(newUser);
});

// Backend API endpoint for updating user role
app.put('/api/users/:id/role', (req, res) => {
  // Verify that the user is not modifying their own role without proper authorization
  if (req.params.id === req.user.id && !isAdmin(req.user)) {
    return res.status(403).json({ error: 'Forbidden' });
  }
  updateUserRole(req.params.id, req.body.newRole);
  res.status(200).json({ success: true });
});

Exploitation & Lab Setup

Red Team

Prerequisites:

• Valid administrator credentials for a Trend Vision One instance.
• Network access to the Trend Vision One API endpoints.

Exploitation Steps:

1. Authenticate as an administrator and obtain a session token.
2. Create a new user with a low-privilege role (e.g., "User") via the API:

   curl -X POST https://api.trendvisionone.com/v1/users \
     -H "Authorization: Bearer <admin_token>" \
     -H "Content-Type: application/json" \
     -d '{"username": "attacker_user", "role": "User"}'
   

3. Log in as the new user and obtain their session token.
4. Send a request to escalate the user's role to "Admin":

   curl -X PUT https://api.trendvisionone.com/v1/users/<new_user_id>/role \
     -H "Authorization: Bearer <new_user_token>" \
     -H "Content-Type: application/json" \
     -d '{"newRole": "Admin"}'
   

5. Verify escalated privileges by accessing administrative endpoints.

Note: This vulnerability has been patched. The above steps are for educational purposes only.

Blue Team

Detection:

• Monitor API logs for unusual role change requests, especially from non-admin users.
• Alert on multiple user creation events from a single administrator account in a short time frame.
• Track session tokens for privilege escalation attempts.

Hunting:

• Search for API calls to /v1/users/*/role with a newRole value higher than the user's current role.
• Correlate user creation events with subsequent role changes from the same IP address.

Mitigation:

• Ensure backend services enforce strict authorization checks for all role-related operations.
• Implement audit logging for all user management actions.
• Apply the vendor's backend patch (already applied).

Indicators of Compromise (IOCs)

• Network IOCs:
  • API requests to /v1/users with POST method from non-admin accounts (if possible).
  • API requests to /v1/users/*/role with PUT method and newRole set to a higher privilege level.
• Log IOCs:
  • Multiple user creation events from the same administrator within a short period.
  • Role change events where the user ID matches the requester ID and the new role is "Admin".
• Behavioral IOCs:
  • Users with unexpected administrative privileges.
  • Accounts created by administrators that later exhibit suspicious activity.

Detection Engineering

YARA Rule

rule CVE_2025_31283_Privilege_Escalation {
    meta:
        description = "Detects potential privilege escalation attempts via role change API calls"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-31283"
    strings:
        $role_change = "/v1/users/" ascii wide nocase
        $new_role = "newRole" ascii wide nocase
        $admin_role = "Admin" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2025-31283 - Privilege Escalation via User Role Change
id: 8a3f7c2e-5b1d-4a9f-8c6e-2d1f3a4b5c6d
status: experimental
description: Detects attempts to change a user role to a higher privilege level
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: trend_vision_one
detection:
    selection:
        http.method: 'PUT'
        http.url|contains: '/v1/users/'
        http.url|endswith: '/role'
        json.newRole: 'Admin'
    condition: selection
falsepositives:
    - Legitimate admin actions (should be rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-31283 - Privilege Escalation via User Role Change";
    flow:to_server,established;
    content:"PUT"; http_method;
    content:"/v1/users/"; http_uri;
    content:"/role"; http_uri;
    content:"newRole"; http_client_body;
    content:"Admin"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

• Verify that the Trend Vision One backend service has been updated (vendor has already applied the fix).
• Review user accounts for any unauthorized privilege escalations.
• Rotate credentials for any accounts created by administrators during the vulnerable period.

Long-Term Measures:

• Implement strict server-side authorization checks for all user management APIs.
• Enable comprehensive audit logging for role changes and user creation.
• Conduct regular security reviews of RBAC implementations.
• Apply the principle of least privilege to all user roles.

Vendor Communication:

• No further action required as the vulnerability has been addressed on the backend.

Valters IT