A Use of Externally-Controlled Format String vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).

If DNS Domain Generation Algorithm (DGA) detection or tunnel detection, and DNS-filtering traceoptions are configured, and specific valid transit DNS traffic is received this causes a PFE crash and restart, leading to a Denial of Service.

This issue affects Junos OS:

• All versions before 21.4R3-S6,
• 22.2 versions before 22.2R3-S3,
• 22.3 versions before 22.3R3-S3,
• 22.4 versions before 22.4R3,
• 23.2 versions before 23.2R2.

To be exposed to this issue at least one of DGA or tunnel detection needs to be configured:

[ services security-metadata-streaming policy <name> dns detections dga ]
[ services security-metadata-streaming policy <name> dns detections tunneling ]

and DNS traceoptions have to be configured:

[ services dns-filtering traceoptions ... ]

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

This issue was seen during production usage.

The following software releases have been updated to resolve this specific issue: 21.4R3-S6, 22.2R3-S3, 22.3R3-S3, 22.4R3, 23.2R2, 23.4R1, and all subsequent releases.
 

This issue is being tracked as 1755484 which is visible on the Customer Support website.
 

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

2024-07-10: Initial Publication
2024-09-13: Minor formatting change to CVSS field

• 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
• https://www.cve.org/CVERecord?id=CVE-2024-39529