When sFlow is enabled and it monitors a packet forwarded via ECMP, a buffer management vulnerability in the dcpfe process of Juniper Networks Junos OS on QFX10K Series systems allows an attacker to cause the Packet Forwarding Engine (PFE) to crash and restart by sending specific genuine packets to the device, resulting in a Denial of Service (DoS) condition.
 

The dcpfe process tries to copy more data into a smaller buffer, which overflows and corrupts the buffer, causing a crash of the dcpfe process. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition.

This issue affects Juniper Networks Junos OS on QFX10K Series:

• All versions prior to 19.4R3-S9;
• 20.2 versions prior to 20.2R3-S6;
• 20.3 versions prior to 20.3R3-S6;
• 20.4 versions prior to 20.4R3-S5;
• 21.1 versions prior to 21.1R3-S4;
• 21.2 versions prior to 21.2R3-S3;
• 21.3 versions prior to 21.3R3-S2;
• 21.4 versions prior to 21.4R2-S2, 21.4R3;
• 22.1 versions prior to 22.1R2;
• 22.2 versions prior to 22.2R1-S2, 22.2R2.

This issue only affects systems with sFlow enabled. An example sFlow configuration is shown below:

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-2023-22399.
 

The following software releases have been updated to resolve this specific issue: 19.4R3-S9, 20.2R3-S6, 20.3R3-S6, 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S2, 21.4R2-S2, 21.4R3, 22.1R2, 22.2R1-S2, 22.2R2, 22.3R1, and all subsequent releases.
 

This issue is being tracked as 1668330.
 

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

1. Prevent sflow from monitoring ECMP forwarded packets.
2. Temporarily disable sFlow to mitigate this issue.

• 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
• https://www.juniper.net/documentation/us/en/software/junos/network-mgmt/topics/topic-map/sflow-monitoring-technology.html
• CVE-2023-22399 at cve.mitre.org