A vulnerability in class-of-service (CoS) queue management in Juniper Networks Junos OS on the ACX2K Series devices allows an unauthenticated network-based attacker to cause a Denial of Service (DoS).
 

Specific packets are being incorrectly routed to a queue used for other high-priority traffic such as BGP, PIM, ICMP, ICMPV6 ND and ISAKMP. Due to this misclassification of traffic, receipt of a high rate of these specific packets will cause delays in the processing of other traffic, leading to a Denial of Service (DoS). Continued receipt of this amount of traffic will create a sustained Denial of Service (DoS) condition.

This issue affects Juniper Networks Junos OS on ACX2K Series:

• All versions prior to 19.4R3-S9;
• All 20.2 versions;
• 20.3 versions prior to 20.3R3-S6;
• 20.4 versions prior to 20.4R3-S4;
• All 21.1 versions;
• 21.2 versions prior to 21.2R3-S3.

Note: This issues affects legacy ACX2K Series PPC-based devices. This platform reached Last Supported Version (LSV) as of the Junos OS 21.2 Release.

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

This issue was seen during production usage.

This issue has been assigned CVE-2023-22391.
 

The following software releases have been updated to resolve this specific issue: Junos OS 19.4R3-S9, 20.3R3-S6, 20.4R3-S4, and 21.2R3-S3.

Note: Legacy ACX2000 Series PPC-based devices have reached Last Supported Version (LSV) as of Junos OS 21.2.

This issue is being tracked as 1637615.

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

• 2023-01-11: 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-2023-22391 at cve.mitre.org