CVE-2024-45482

Remediation/Mitigation Strategy: CVE-2024-45482 - B&R APROL SSH Server Vulnerability

This document outlines the remediation and mitigation strategy for CVE-2024-45482, an “Inclusion of Functionality from Untrusted Control Sphere” vulnerability affecting the SSH server in B&R APROL systems.

1. Vulnerability Description:

  • CVE ID: CVE-2024-45482
  • Vendor: Asea Brown Boveri Ltd. (ABB) / B&R
  • Product: B&R APROL
  • Affected Versions: < 4.4-00P1
  • Description: The vulnerability resides in the SSH server component of B&R APROL. It allows an authenticated local attacker, originating from a trusted remote server, to execute malicious commands on the APROL system. This is due to the inclusion of functionality from an untrusted control sphere. Essentially, a compromised (or malicious) server trusted by the APROL system can inject malicious commands into the SSH session running on the APROL system.
  • Attack Vector: Network
  • Attack Complexity: High (Requires pre-existing trust relationship)
  • Authentication: Required (Valid user account on the trusted remote server)
  • Confidentiality Impact: High (Potential access to sensitive data)
  • Integrity Impact: High (Potential modification or deletion of data)
  • Availability Impact: High (Potential system outage or denial of service)

2. Severity:

  • CVSSv3 Score: 8.5 (High)
  • Vector: AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
  • Rationale: While the vulnerability requires authentication and a pre-existing trust relationship, its potential impact is severe. Successful exploitation grants the attacker a high degree of control over the APROL system, allowing them to compromise confidentiality, integrity, and availability. The impact is considered ‘changed scope’ because the attacker can execute commands on a system outside of their initial access.

3. Known Exploits:

  • The provided data does not explicitly mention publicly available exploits. However, the CVSS score and vulnerability description suggest that exploitation is possible. Organizations should treat this vulnerability with urgency, assuming that exploits may be developed and released in the future, or that internal knowledge of the vulnerability exists.

4. Remediation Strategy:

The primary goal of the remediation strategy is to eliminate the vulnerability by updating to a patched version of the APROL software.

  • Immediate Action (Patching):

    • Upgrade to a fixed version: The most effective solution is to upgrade to a version of B&R APROL that contains a fix for CVE-2024-45482. Contact ABB/B&R support to obtain the appropriate patch or upgrade package. Prioritize patching systems that are directly accessible from untrusted networks.
    • Test Patch: Before deploying the patch to production systems, thoroughly test it in a non-production environment that mirrors the production environment as closely as possible. Verify that the patch resolves the vulnerability and does not introduce any new issues or regressions.

  • Short-Term Mitigation (If Patching is Not Immediately Possible):

    If an immediate patch cannot be applied, consider the following mitigation steps:

    • Restrict Access: Implement stricter access controls to the APROL system. Limit the number of trusted remote servers that can connect to the APROL SSH server. Review and tighten firewall rules.
    • Strengthen Authentication: Enforce multi-factor authentication (MFA) for SSH access to the APROL system. This will add an extra layer of security and make it more difficult for attackers to gain access, even if they have compromised a trusted remote server. Consider using SSH keys instead of passwords.
    • Harden SSH Configuration: Review and harden the SSH server configuration on the APROL system. Disable unnecessary features and protocols. Use strong cryptographic algorithms. Consider using a more secure SSH implementation if possible. Specifically:
      • Disable unused SSH features: Disable X11 forwarding, agent forwarding, and other features that are not required.
      • Configure allowed users: Specify the users who are allowed to connect via SSH using the AllowUsers directive in the sshd_config file.
      • Limit connection attempts: Use MaxAuthTries to limit the number of authentication attempts.
      • Set idle timeout: Use ClientAliveInterval and ClientAliveCountMax to automatically disconnect idle sessions.
    • Intrusion Detection/Prevention: Deploy intrusion detection/prevention systems (IDS/IPS) to monitor network traffic for suspicious activity. Configure alerts for potential exploitation attempts. Ensure that the IDS/IPS is properly configured to detect and block malicious commands being executed via SSH.
    • Monitoring and Logging: Enable comprehensive logging on the APROL system and the SSH server. Monitor logs for suspicious activity, such as failed login attempts, unauthorized commands, and unexpected system behavior. Use a Security Information and Event Management (SIEM) system to centralize log collection and analysis. Regularly review logs.
    • Principle of Least Privilege: Ensure users only have the minimum necessary permissions to perform their job functions. Review and adjust permissions as needed.

  • Long-Term Security Practices:

    • Vulnerability Management Program: Implement a comprehensive vulnerability management program to identify and address security vulnerabilities in a timely manner.
    • Security Awareness Training: Provide regular security awareness training to employees to educate them about phishing attacks, social engineering, and other threats.
    • Regular Security Audits: Conduct regular security audits of the APROL system and the network infrastructure to identify potential weaknesses.
    • Secure Configuration Management: Establish and maintain secure configuration standards for all systems. Regularly review and update configurations to ensure they are in compliance with security best practices.
    • Network Segmentation: Implement network segmentation to isolate critical systems, such as the APROL system, from other parts of the network. This will limit the potential impact of a successful attack.

5. Communication:

  • Internal: Communicate the vulnerability details and remediation plan to all relevant stakeholders, including IT staff, security personnel, and system administrators.
  • External: Follow ABB/B&R’s recommended communication procedures for reporting security vulnerabilities. Provide feedback to ABB/B&R on the effectiveness of their security measures.

6. Validation:

  • After applying the patch or implementing the mitigation steps, validate that the vulnerability has been successfully addressed. This can be done by:
    • Re-scanning with a vulnerability scanner: Use a vulnerability scanner to verify that CVE-2024-45482 is no longer present.
    • Manual testing: Conduct manual testing to attempt to exploit the vulnerability.
    • Reviewing logs: Monitor logs for any signs of suspicious activity.

7. Disclaimer:

This remediation/mitigation strategy is based on the information provided and general security best practices. It is recommended to consult with ABB/B&R and your internal security team to develop a strategy that is tailored to your specific environment. Always test changes in a non-production environment before deploying them to production.

Assigner

Date

  • Published Date: 2025-03-25 05:15:39
  • Updated Date: 2025-03-25 05:15:39

More Details

CVE-2024-45482