CVE-2025-30656
Vulnerability Remediation/Mitigation Strategy
Vulnerability Description:
An Improper Handling of Additional Special Element vulnerability exists in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series with MS-MPC, MS-MIC and SPC3, and SRX Series. This vulnerability is triggered by specifically formatted SIP invites processed by the SIP ALG, resulting in memory corruption and a crash of the FPC. Repeated exploitation can lead to a sustained Denial-of-Service (DoS).
Severity:
High (CVSS v3.1 Score: 8.7)
Known Exploit:
Attackers can craft specific SIP invite packets that, when processed by the SIP ALG, cause a memory corruption and FPC crash, leading to DoS. The system automatically recovers with an FPC restart, but subsequent SIP invites will cause the crash again, creating a sustained DoS condition. This exploit is network-based and does not require authentication.
Affected Versions:
Junos OS on MX Series and SRX Series:
- all versions before 21.2R3-S9
- 21.4 versions before 21.4R3-S10
- 22.2 versions before 22.2R3-S6
- 22.4 versions before 22.4R3-S5
- 23.2 versions before 23.2R2-S3
- 23.4 versions before 23.4R2-S3
- 24.2 versions before 24.2R1-S2, 24.2R2
Remediation/Mitigation Steps:
Upgrade Junos OS: The primary remediation is to upgrade Junos OS to a fixed version. This requires scheduling a maintenance window. Upgrade to one of the following versions or later:
- 21.2R3-S9
- 21.4R3-S10
- 22.2R3-S6
- 22.4R3-S5
- 23.2R2-S3
- 23.4R2-S3
- 24.2R1-S2, or any version after 24.2R2
Disable SIP ALG (if possible): As a temporary mitigation, if SIP ALG functionality is not essential, disable it. This will prevent the vulnerable code from being executed. The specific command to disable SIP ALG will depend on your Junos OS configuration, but typically involves removing or deactivating the SIP ALG application under the security policies. Note: Disabling SIP ALG might impact VoIP functionality. Perform thorough testing after disabling SIP ALG to ensure essential services are not affected.
Rate Limiting/Traffic Filtering: Implement rate limiting or traffic filtering rules to restrict the rate of SIP INVITE packets entering the network. This can reduce the impact of a potential DoS attack, but it will not prevent exploitation. Use appropriate source and destination criteria for filtering, and configure sensible thresholds for rate limiting. Consider using firewall filters or CoS (Class of Service) features.
Monitor System Logs: Monitor system logs for FPC crashes and SIP ALG-related error messages. Correlate this with network traffic patterns to detect potential exploitation attempts. Configure alerts to notify administrators of unusual activity.
Intrusion Detection/Prevention Systems (IDS/IPS): Update your IDS/IPS signatures to detect and potentially block malicious SIP INVITE packets designed to exploit this vulnerability. Test the updated signatures in a non-production environment before deploying them to production.
Vendor Communication: Consult Juniper Networks’ security advisories and documentation for any updated information or recommendations regarding this vulnerability. Follow their recommended best practices.
Testing: After implementing any of the above mitigation steps, thoroughly test the system to ensure that the changes have not introduced any new issues. This includes testing core network functionality and any services that rely on SIP ALG.
Priority: High - Implement immediately, especially in environments with high SIP traffic or exposure to untrusted networks.
Assigner
- Juniper Networks, Inc. [email protected]
Date
- Published Date: 2025-04-09 20:15:30
- Updated Date: 2025-04-09 20:15:30