CVE-2022-30356

Executive Summary

CVE-2022-30356 is a privilege escalation vulnerability in OvalEdge versions 5.2.8.0 and earlier. The flaw allows an authenticated user with the OE_ADMIN role to escalate their privileges by sending a crafted POST request to the /user/assignuserrole endpoint. By manipulating the userid and role parameters, an attacker can assign any role (including higher-privileged roles) to any user, effectively bypassing intended access controls. This vulnerability is classified as a privilege escalation (CWE-269) and aligns with MITRE ATT&CK tactic T1068 (Exploitation for Privilege Escalation). No official patch has been released, and the vendor has not provided a fix.

Supply Chain & Package Security

This vulnerability is not related to an open-source package (NPM, PyPI, Go, Ruby). It affects a proprietary enterprise application (OvalEdge). Therefore, supply chain security concerns are limited to the vendor's software distribution and update mechanisms.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0 in the NVD data, which is likely a placeholder. Based on the vulnerability description, a reasonable CVSS v3.1 vector would be:

• Attack Vector (AV): Network (N) – The attack is performed over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): Low (L) – The attacker needs an authenticated session with OE_ADMIN role.
• User Interaction (UI): None (N) – No user interaction is required.
• Scope (S): Unchanged (U) – The vulnerable component and the impacted component are the same.
• Confidentiality (C): High (H) – An attacker can gain access to sensitive data.
• Integrity (I): High (H) – An attacker can modify data or assign roles.
• Availability (A): High (H) – An attacker could potentially disrupt operations.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Estimated Base Score: 8.8 (High)

Threat Level: High. The vulnerability requires authentication but allows a user with OE_ADMIN privileges to escalate to any role, potentially gaining full administrative control over the OvalEdge application.

Deep Dive & Mechanics

The vulnerability resides in the /user/assignuserrole endpoint. The application fails to properly validate whether the authenticated user has the authority to assign a specific role to another user. The OE_ADMIN role is intended to allow user management, but the application does not enforce a hierarchical check to prevent an OE_ADMIN from assigning themselves or others a higher-privileged role (e.g., OE_SUPER_ADMIN).

The POST request parameters userid and role are directly used to update the user-role mapping in the backend database. The server-side code likely executes a query similar to:

UPDATE user_roles SET role_id = :role WHERE user_id = :userid

Without verifying that the requesting user's role is superior to the role being assigned, an attacker can simply change the role parameter to a higher-privileged role ID.

Vulnerable vs. Patched Code

Since no official patch is available, a comparison is based on expected secure implementation.

Vulnerable Code (Conceptual):

@app.route('/user/assignuserrole', methods=['POST'])
def assign_user_role():
    userid = request.form['userid']
    role = request.form['role']
    # No privilege check
    db.execute("UPDATE user_roles SET role_id = ? WHERE user_id = ?", (role, userid))
    return "Role assigned"

Patched Code (Conceptual):

@app.route('/user/assignuserrole', methods=['POST'])
def assign_user_role():
    current_user_role = get_current_user_role()
    target_role = get_role_by_id(request.form['role'])
    # Check if current user's role is higher than the target role
    if current_user_role.priority >= target_role.priority:
        return "Forbidden", 403
    userid = request.form['userid']
    db.execute("UPDATE user_roles SET role_id = ? WHERE user_id = ?", (target_role.id, userid))
    return "Role assigned"

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Access to an OvalEdge instance (version <= 5.2.8.0).
• Valid credentials for a user with the OE_ADMIN role.

Exploitation Steps:

1. Authenticate to the OvalEdge web interface and obtain a session cookie (e.g., JSESSIONID).
2. Craft a POST request to the /user/assignuserrole endpoint with the following parameters:
   • userid: The ID of the target user (can be the same as the attacker's user ID).
   • role: The ID of a higher-privileged role (e.g., OE_SUPER_ADMIN).
3. Send the request using a tool like curl:

curl -X POST https://target-ovaledge.com/user/assignuserrole \
  -H "Cookie: JSESSIONID=valid_session_id" \
  -d "userid=1&role=2"

4. Verify escalation by accessing a restricted endpoint or checking the user's role in the application.

Expected Outcome: The target user (or the attacker) is now assigned the higher-privileged role, granting full administrative access.

Blue Team (Detection & Hardening)

Detection:

• Monitor logs for POST requests to /user/assignuserrole with unusual role parameter values.
• Alert on any role assignment where the role parameter corresponds to a higher-privileged role than the requesting user's role.

Hardening:

• Implement server-side validation to ensure that a user can only assign roles that are equal to or lower than their own role.
• Apply the principle of least privilege: the OE_ADMIN role should not be able to assign OE_SUPER_ADMIN or other critical roles.
• Use a Web Application Firewall (WAF) to block requests with suspicious role parameter values.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /user/assignuserrole with parameters userid and role.
  • Unusual role parameter values (e.g., role IDs that correspond to OE_SUPER_ADMIN or other high-privilege roles).
• System IOCs:
  • Audit logs showing unexpected role assignments.
  • User accounts with elevated privileges that were not granted through normal administrative processes.
• File IOCs:
  • Modified database entries in the user_roles table.

Detection Engineering

YARA Rule

rule CVE_2022_30356_OvalEdge_PrivEsc {
    meta:
        description = "Detects exploitation attempts of CVE-2022-30356 in OvalEdge logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2022-30356"
    strings:
        $s1 = "/user/assignuserrole" ascii wide nocase
        $s2 = "userid=" ascii wide nocase
        $s3 = "role=" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: OvalEdge Privilege Escalation via /user/assignuserrole
id: 8a4b3c2d-1e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects POST requests to /user/assignuserrole with role parameter indicating privilege escalation
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/user/assignuserrole'
        cs-uri-query|contains: 'role='
    condition: selection
falsepositives:
    - Legitimate role assignments by authorized administrators
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2022-30356 OvalEdge Privilege Escalation Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/user/assignuserrole"; http_uri; content:"role="; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade to a patched version of OvalEdge if available. Contact the vendor for a fix.
2. Restrict access to the /user/assignuserrole endpoint using network-level controls (e.g., firewall rules) to only allow trusted IP addresses.
3. Review and audit all user roles and permissions to ensure no unauthorized privilege escalation has occurred.

Long-term Mitigations:

1. Implement role-based access control (RBAC) with strict hierarchical validation.
2. Enable detailed logging for all role assignment operations.
3. Conduct regular security assessments and penetration testing on the OvalEdge application.
4. Apply the principle of least privilege to all user roles.

Workaround:

• If patching is not possible, consider disabling the /user/assignuserrole endpoint or modifying the application code to add privilege checks.

Valters IT