An Improper Check for Unusual or Exceptional Conditions vulnerability in the SIP ALG of Juniper Networks Junos OS on SRX Series and MX Series allows an unauthenticated network-based attacker to cause an integrity impact in connected networks.

If the SIP ALG is configured and a device receives a specifically malformed SIP packet, the device prevents this packet from being forwarded, but any subsequently received retransmissions of the same packet are forwarded as if they were valid.

This issue affects Juniper Networks Junos OS on SRX Series and MX Series:

• 20.4 versions prior to 20.4R3-S5;
• 21.1 versions prior to 21.1R3-S4;
• 21.2 versions prior to 21.2R3-S4;
• 21.3 versions prior to 21.3R3-S3;
• 21.4 versions prior to 21.4R3-S2;
• 22.1 versions prior to 22.1R2-S2, 22.1R3;
• 22.2 versions prior to 22.2R2-S1, 22.2R3;
• 22.3 versions prior to 22.3R1-S2, 22.3R2.

This issue doesn't not affected releases prior to 20.4R1.

To be affected the SIP ALG needs to be enabled, either implicitly / by default or by way of configuration. Please verify on SRX, and MX with SPC3 with:

Please verify on MX whether the following is configured:

where either

an application or application-set refers to SIP:

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was found during internal product security testing or research.

This issue has been assigned CVE-2023-44198.

The following software releases have been updated to resolve this specific issue: 20.4R3-S5, 21.1R3-S4, 21.2R3-S4, 21.3R3-S3, 21.4R3-S2, 22.1R2-S2, 22.1R3, 22.2R2-S1, 22.2R3, 22.3R1-S2, 22.3R2, 22.4R1, and all subsequent releases.

This issue is being tracked as PR 1693379 which is visible on the Customer Support website.

Note: Juniper SIRT's policy [juniper.net] is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

2023-10-11: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2023-44198 at cve.mitre.org
• https://supportportal.juniper.net/JSA73164 [juniper.net]