CVE-2025-27925

Remediation/Mitigation Strategy: CVE-2025-27925 - Nintex Automation Insecure Deserialization

Vulnerability: Insecure Deserialization

Product: Nintex Automation

Versions Affected: 5.6 and 5.7

Fixed Version: 5.8

Severity: High (CVSS Score: 8.5)

Description:

Nintex Automation versions 5.6 and 5.7 are vulnerable to insecure deserialization. This vulnerability arises from the improper handling of user-supplied input during deserialization processes. Attackers can exploit this flaw to inject malicious serialized objects into the application. When the application attempts to deserialize these objects, it can lead to arbitrary code execution, denial of service, or data compromise. Essentially, the software trusts user input too much when reconstructing objects from serialized data.

Known Exploit:

Due to the nature of insecure deserialization, a successful exploit would involve crafting a malicious serialized object containing code or commands that the Nintex Automation server will execute upon deserialization. While the specific details of the exploit might vary depending on the Nintex Automation configuration and underlying dependencies, the general approach is as follows:

  1. Identify Deserialization Points: Locate endpoints in the Nintex Automation application where user-supplied data is deserialized. This could be within web services, APIs, or other communication channels.
  2. Craft Malicious Payload: Create a serialized object that, when deserialized, will trigger the desired malicious action. This might involve:
    • Executing arbitrary code. This often involves leveraging existing libraries or classes available to the Nintex Automation runtime to perform system calls or execute commands.
    • Modifying or deleting sensitive data.
    • Creating new user accounts with elevated privileges.
    • Denial of Service (DoS): Creating a serialized object that consumes excessive resources or causes the application to crash upon deserialization.
  3. Send Payload: Transmit the malicious serialized object to the identified deserialization point within the Nintex Automation application.
  4. Exploitation: Upon deserialization, the malicious code/actions will be executed by the Nintex Automation server, granting the attacker control or access to sensitive information.

Impact:

Successful exploitation of this vulnerability could allow an attacker to:

  • Gain Remote Code Execution (RCE): Execute arbitrary commands on the Nintex Automation server.
  • Compromise Data: Steal or modify sensitive data stored within or accessed by the Nintex Automation application.
  • Denial of Service (DoS): Crash the Nintex Automation server or render it unavailable to legitimate users.
  • Privilege Escalation: Gain elevated privileges within the Nintex Automation system or on the underlying server.

Remediation/Mitigation Strategy:

The primary remediation is to upgrade to Nintex Automation version 5.8 or later. This version contains a fix for the insecure deserialization vulnerability.

In addition to upgrading, consider the following mitigation strategies (especially if an immediate upgrade is not possible):

  1. Input Validation and Sanitization: While not a complete solution, implement rigorous input validation and sanitization at all endpoints that handle user-supplied data. This can help to prevent the injection of malicious data in the first place. However, understand that this is only a defense in depth and should not be relied upon as the primary solution.
  2. Restrict Deserialization: If possible, limit the classes that can be deserialized. Implement a whitelist approach where only trusted classes are allowed to be deserialized. This significantly reduces the attack surface by preventing the deserialization of malicious classes.
  3. Monitor System Activity: Implement robust monitoring and logging to detect suspicious activity, such as unusual process executions, file modifications, or network connections. This can help to identify and respond to an attempted exploit.
  4. Principle of Least Privilege: Ensure that the Nintex Automation service account has the minimum necessary privileges to perform its tasks. This limits the impact of a successful exploit. If an attacker gains code execution, they will only be able to perform actions within the context of the service account.
  5. Web Application Firewall (WAF): Deploy a Web Application Firewall (WAF) in front of the Nintex Automation application. Configure the WAF to detect and block common attack patterns associated with deserialization vulnerabilities. This can provide an additional layer of protection.
  6. Regular Security Assessments: Conduct regular security assessments and penetration testing to identify and address potential vulnerabilities in the Nintex Automation environment.

Steps to Implement:

  1. Plan and Schedule Upgrade: Coordinate an upgrade to Nintex Automation 5.8 or later. Ensure sufficient testing is performed in a non-production environment before applying the upgrade to production.
  2. Implement Input Validation/Sanitization: Review all endpoints that handle user-supplied data and implement appropriate input validation and sanitization routines.
  3. Configure Whitelisting (If Possible): Investigate the possibility of implementing a deserialization whitelist to restrict the allowed classes. Consult the Nintex Automation documentation or vendor support for guidance on this.
  4. Review Monitoring and Logging: Ensure that adequate monitoring and logging is in place to detect suspicious activity. Configure alerts for events such as unusual process executions or file modifications.
  5. Review Service Account Privileges: Review the privileges assigned to the Nintex Automation service account and ensure that it adheres to the principle of least privilege.
  6. Deploy WAF (If Applicable): If a WAF is available, deploy it in front of the Nintex Automation application and configure it to protect against deserialization attacks.
  7. Conduct Security Assessment: Schedule a security assessment to validate the effectiveness of the remediation and mitigation measures.

Note: This remediation/mitigation strategy provides general guidance. The specific steps required will vary depending on the Nintex Automation configuration and environment. Consult the Nintex Automation documentation and vendor support for more detailed information and recommendations. Prioritize upgrading to the latest secure version as the most effective solution.

Assigner

Date

  • Published Date: 2025-03-10 00:00:00
  • Updated Date: 2025-03-10 23:15:35

More Details

CVE-2025-27925