A Denial of Service (DoS) vulnerability in the processing of a flood of specific ARP traffic in Juniper Networks Junos OS on the EX4300 switch, sent from the local broadcast domain, may allow an unauthenticated network-adjacent attacker to trigger a PFEMAN watchdog timeout, causing the Packet Forwarding Engine (PFE) to crash and restart. After the restart, transit traffic will be temporarily interrupted until the PFE is reprogrammed. In a virtual chassis (VC), the impacted Flexible PIC Concentrator (FPC) may split from the VC temporarily, and join back into the VC once the PFE restarts.

Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition.
 

This issue affects Juniper Networks Junos OS on the EX4300:

• All versions prior to 15.1R7-S12;
• 18.4 versions prior to 18.4R2-S10, 18.4R3-S11;
• 19.1 versions prior to 19.1R3-S8;
• 19.2 versions prior to 19.2R1-S9, 19.2R3-S4;
• 19.3 versions prior to 19.3R3-S5;
• 19.4 versions prior to 19.4R2-S6, 19.4R3-S7;
• 20.1 versions prior to 20.1R3-S3;
• 20.2 versions prior to 20.2R3-S3;
• 20.3 versions prior to 20.3R3-S2;
• 20.4 versions prior to 20.4R3-S1;
• 21.1 versions prior to 21.1R3;
• 21.2 versions prior to 21.2R2-S1, 21.2R3;
• 21.3 versions prior to 21.3R1-S2, 21.3R2.

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-2022-22191.

The following software releases have been updated to resolve this specific issue: Junos OS 15.1R7-S12, 18.4R2-S10, 18.4R3-S11, 19.1R3-S8, 19.2R1-S9, 19.2R3-S4, 19.3R3-S5, 19.4R2-S6, 19.4R3-S7, 20.1R3-S3, 20.2R3-S3, 20.3R3-S2, 20.4R3-S1, 21.1R3, 21.2R2-S1, 21.2R3, 21.3R1-S2, 21.3R2, 21.4R1, and all subsequent releases.

This issue is being tracked as PR 1613275 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).
 

Implementation

Software Releases, patches and updates are available at https://support.juniper.net/support/downloads/.

• 2022-04-13: 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-2022-22191 at cve.mitre.org