CVE-2026-7198

Executive Summary

CVE-2026-7198 is a critical Improper Access Control vulnerability (CWE-284) affecting Progress Sitefinity, a popular .NET-based web content management system (CMS). The flaw resides in the web services layer of Sitefinity versions 15.4.8623 and earlier, prior to the patched version 15.4.8630. A remote, unauthenticated attacker can exploit this vulnerability to bypass access controls and access restricted content, leading to a full compromise of confidentiality, integrity, and availability of the affected installation. The CVSS score of 9.8 underscores the severity, as no authentication or user interaction is required for exploitation. The EPSS score is currently 0.0%, indicating no active exploitation in the wild at the time of analysis, but the high impact and ease of exploitation make this a high-priority patching target.

Supply Chain & Package Security

This vulnerability is not in an open-source package manager (NPM, PyPI, Go, Ruby) but in a commercial .NET CMS. The supply chain risk is limited to the direct use of Progress Sitefinity. Organizations should verify their Sitefinity version and apply the vendor patch immediately. No open-source patch data is available from OSV or GitHub.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 9.8 (Critical)
• Attack Vector (AV): Network – Exploitable remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): None – No authentication needed.
• User Interaction (UI): None – No user action required.
• Scope (S): Unchanged – The vulnerable component is the affected system.
• Confidentiality (C): High – Full read access to all restricted content.
• Integrity (I): High – Full write access to modify or delete content.
• Availability (A): High – Full ability to disrupt service.

Threat Level: Critical. The vulnerability allows a complete takeover of the Sitefinity installation with no prior access. It is a prime target for ransomware groups and data thieves.

Deep Dive & Mechanics

The vulnerability is rooted in improper access control checks within Sitefinity's web services API. Sitefinity exposes various RESTful and SOAP web services for content management, user administration, and site configuration. In the affected versions, these services fail to enforce proper authorization checks for certain endpoints. Specifically, the CWE-284 flaw means that the application does not validate whether a user has the necessary permissions to access a resource or perform an action.

Mechanism:

1. An unauthenticated attacker sends a crafted HTTP request to a vulnerable web service endpoint (e.g., /Sitefinity/Services/Content/... or /api/default/...).
2. The server processes the request without verifying the user's identity or role.
3. The attacker can then read, create, modify, or delete any content, including pages, users, roles, and configuration settings.
4. This can lead to privilege escalation (e.g., creating an admin account), data exfiltration, or complete site defacement.

The vulnerability is present in the 15.4.8623 build and was fixed in 15.4.8630. The patch likely involves adding authorization checks (e.g., [Authorize] attributes or manual role validation) to the affected service endpoints.

Vulnerable vs. Patched Code

The exact code change is not publicly available, but based on the CWE, the fix involves adding access control checks.

Vulnerable Code (Conceptual C#):

[ServiceContract]
public interface IContentService
{
    [OperationContract]
    [WebGet(UriTemplate = "/content/{id}")]
    ContentItem GetContent(string id);
}

public class ContentService : IContentService
{
    public ContentItem GetContent(string id)
    {
        // VULNERABLE: No authorization check
        return DataRepository.GetContent(id);
    }
}

Patched Code (Conceptual C#):

[ServiceContract]
public interface IContentService
{
    [OperationContract]
    [WebGet(UriTemplate = "/content/{id}")]
    ContentItem GetContent(string id);
}

public class ContentService : IContentService
{
    [PrincipalPermission(SecurityAction.Demand, Role = "Administrators")]
    public ContentItem GetContent(string id)
    {
        // PATCHED: Authorization check added
        if (!User.Identity.IsAuthenticated || !User.IsInRole("Administrators"))
        {
            throw new SecurityException("Access denied.");
        }
        return DataRepository.GetContent(id);
    }
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A vulnerable Sitefinity instance (version 15.4.8623).
• Network access to the web service endpoints.

Exploitation Steps:

1. Reconnaissance: Identify the Sitefinity version and discover web service endpoints. Common paths include:

   • /Sitefinity/Services/Content/ContentService.svc/
   • /api/default/
   • /Sitefinity/Services/Pages/PagesService.svc/

2. Craft Request: Send an unauthenticated GET request to a sensitive endpoint. For example, to list all users:

   GET /Sitefinity/Services/Content/ContentService.svc/users HTTP/1.1
   Host: target.com
   

3. Exploit: If the endpoint is vulnerable, the server will return the data without requiring authentication. For privilege escalation, send a POST request to create a new admin user:

   POST /Sitefinity/Services/Content/ContentService.svc/users HTTP/1.1
   Host: target.com
   Content-Type: application/json
   
   {
     "username": "attacker",
     "password": "P@ssw0rd!",
     "roles": ["Administrators"]
   }
   

4. Post-Exploitation: Use the newly created admin account to access the Sitefinity backend, deploy web shells, or exfiltrate the database.

No public exploit code (Exploit-DB) or Nuclei template is available at this time.

Blue Team (Detection & Hardening)

Detection:

• Monitor for unauthenticated requests to Sitefinity web service endpoints (e.g., /Sitefinity/Services/, /api/).
• Alert on HTTP 200 responses to sensitive endpoints from IPs not in the allowed list.
• Look for anomalous POST requests creating users or modifying roles without prior authentication.

Hardening:

• Immediately upgrade to Sitefinity 15.4.8630 or later.
• If patching is delayed, restrict network access to the Sitefinity web services using a WAF or firewall rules.
• Enable logging for all web service requests and audit logs for user creation/modification.
• Implement additional authentication layers (e.g., VPN, client certificates) for administrative endpoints.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Unauthenticated HTTP requests to /Sitefinity/Services/Content/ContentService.svc/
  • Unauthenticated HTTP requests to /api/default/
  • POST requests to /Sitefinity/Services/Content/ContentService.svc/users with JSON payloads containing "roles": ["Administrators"]
  • Source IPs not in the organization's whitelist accessing these endpoints.

• File IOCs:

  • Unexpected files in the ~/Sitefinity/ directory (e.g., web shells, backdoors).
  • Modified Web.config files with new service endpoints or authentication bypass entries.

• Log IOCs:

  • Event logs showing user creation without a corresponding authentication event.
  • IIS logs showing HTTP 200 responses to /Sitefinity/Services/ from external IPs.

Detection Engineering

YARA Rule

rule CVE_2026_7198_Sitefinity_AccessControl {
    meta:
        description = "Detects potential exploitation of CVE-2026-7198 in Sitefinity logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2026-7198"
    strings:
        $s1 = "/Sitefinity/Services/Content/ContentService.svc/" ascii wide nocase
        $s2 = "/api/default/" ascii wide nocase
        $s3 = "\"roles\":[\"Administrators\"]" ascii wide nocase
        $s4 = "POST /Sitefinity/Services/Content/ContentService.svc/users" ascii wide nocase
    condition:
        any of ($s1, $s2) or ($s3 and $s4)
}

Sigma Rule

title: CVE-2026-7198 - Unauthenticated Access to Sitefinity Web Services
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated HTTP requests to Sitefinity web service endpoints that may indicate exploitation of CVE-2026-7198.
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-7198
logsource:
    category: webserver
    product: iis
detection:
    selection:
        cs-uri-stem|contains:
            - '/Sitefinity/Services/Content/ContentService.svc/'
            - '/api/default/'
        cs-method: 'GET'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate authenticated users accessing these endpoints (should be rare)
level: high

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"CVE-2026-7198 - Unauthenticated Sitefinity Web Service Access";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"/Sitefinity/Services/Content/ContentService.svc/"; http_uri;
    content:"/api/default/"; http_uri;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
    reference:cve,2026-7198;
    priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade to Sitefinity version 15.4.8630 or later. This is the only complete fix.
2. Workaround: If patching is not immediately possible, restrict access to the Sitefinity web services using a Web Application Firewall (WAF) or network ACLs to only allow trusted IPs.
3. Audit: Review IIS logs for any signs of exploitation (unauthenticated requests to /Sitefinity/Services/ or /api/). Check for unauthorized user accounts in the Sitefinity admin panel.

Long-Term Measures:

• Implement a vulnerability management program to ensure timely patching of CMS and other critical software.
• Enable comprehensive logging and monitoring for all web service endpoints.
• Conduct regular security assessments, including penetration testing of web applications.
• Follow the principle of least privilege for all user accounts and service accounts.

Valters IT Signature

Report generated by Valters IT Cyber Threat Intelligence Division. For questions, contact cti@valtersit.com.