CVE-2025-30649

Remediation / Mitigation Strategy: CVE-2025-30649

Vulnerability Description: Improper Input Validation in the syslog stream TCP transport of Juniper Networks Junos OS on MX240, MX480, and MX960 devices with MX-SPC3 Security Services Card. This allows an unauthenticated, network-based attacker to send spoofed packets causing a CPU Denial of Service (DoS) to the MX-SPC3 SPUs.

Severity: High (CVSS Score: 8.7)

Known Exploit: An attacker can send specific, spoofed packets via TCP to the syslog stream. Repeated transmission of these packets will sustain a CPU DoS condition on the MX-SPC3 SPUs, impacting services reliant on the Security Services Card.

Affected Versions:

  • All Junos OS versions before 22.2R3-S6
  • Junos OS 22.4 before 22.4R3-S4
  • Junos OS 23.2 before 23.2R2-S3
  • Junos OS 23.4 before 23.4R2-S4
  • Junos OS 24.2 before 24.2R1-S2 and 24.2R2

Remediation:

  1. Upgrade Junos OS: The primary mitigation is to upgrade to a fixed version of Junos OS. Choose the appropriate upgrade path based on your current version:

    • Upgrade to 22.2R3-S6 or later
    • Upgrade to 22.4R3-S4 or later
    • Upgrade to 23.2R2-S3 or later
    • Upgrade to 23.4R2-S4 or later
    • Upgrade to 24.2R1-S2 or 24.2R2-S1 or later

    Refer to Juniper’s official advisory for the most up-to-date recommendations and download links.

  2. Vendor Patch: Apply the security patch released by Juniper Networks as soon as possible. Follow the provided instructions for installing the patch on your specific device model and Junos OS version.

Mitigation (If immediate patching/upgrade is not possible):

  • Implement Rate Limiting: Implement rate limiting on syslog traffic from untrusted sources to the MX-SPC3 SPU interface to prevent flooding.
  • Access Control Lists (ACLs): Create ACLs to restrict access to the syslog service on the affected interfaces to only trusted sources. Block any unexpected or untrusted IP addresses from sending syslog data.
  • Traffic Analysis: Utilize network monitoring tools to analyze traffic patterns for anomalies related to the syslog service. Look for unusual spikes in syslog traffic from specific sources or patterns indicative of exploitation attempts.
  • Monitor CPU Utilization: Regularly monitor the CPU utilization of the MX-SPC3 SPUs using the show services service-sets summary command. Look for consistently high CPU utilization (e.g., 99% or more) as an indicator of a potential DoS attack.

Monitoring and Detection:

  • CPU Utilization Alerts: Configure monitoring systems to generate alerts when the CPU utilization of the MX-SPC3 SPUs exceeds a predefined threshold (e.g., 80%).
  • Syslog Event Analysis: Implement a Security Information and Event Management (SIEM) system or similar log analysis tool to collect and analyze syslog events for suspicious patterns, such as a high volume of syslog messages from specific sources or error messages related to the syslog service.
  • Network Intrusion Detection/Prevention System (IDS/IPS): Update signatures on IDS/IPS systems to detect and block known exploitation attempts targeting the vulnerability.

Testing:

  • After applying the patch or implementing mitigations, thoroughly test the syslog functionality and overall system performance to ensure that the fixes have not introduced any unintended side effects.
  • Simulate attack scenarios in a controlled environment to validate the effectiveness of the implemented mitigations.

Communication:

  • Inform relevant stakeholders about the vulnerability and the implemented remediation/mitigation strategy.
  • Provide regular updates on the progress of the remediation efforts.

Assigner

Date

  • Published Date: 2025-04-09 20:15:28
  • Updated Date: 2025-04-09 20:15:28

More Details

CVE-2025-30649