CVE-2022-22191 Explained : Impact and Mitigation
Learn about CVE-2022-22191, a Denial of Service (DoS) vulnerability in Juniper Networks Junos OS on the EX4300 switch. Understand the impact, affected systems, exploitation mechanism, and mitigation steps.
A Denial of Service (DoS) vulnerability has been identified in Juniper Networks Junos OS on the EX4300 switch. An attacker can exploit this vulnerability to trigger a PFEMAN watchdog timeout, leading to the Packet Forwarding Engine (PFE) crashing and restarting, causing interruptions in transit traffic.
Understanding CVE-2022-20657
This CVE encompasses a vulnerability in Juniper Networks Junos OS that allows an unauthenticated attacker to send specific ARP traffic, leading to a Denial of Service (DoS) condition.
What is CVE-2022-20657?
A Denial of Service (DoS) vulnerability in the processing of ARP traffic in Juniper Networks Junos OS on the EX4300 switch can be exploited by a network-adjacent attacker to crash the Packet Forwarding Engine (PFE) and cause transit traffic interruptions.
The Impact of CVE-2022-20657
The vulnerability can result in a PFEMAN watchdog timeout, leading to PFE restarting and temporary interruptions in transit traffic, potentially causing sustained DoS conditions.
Technical Details of CVE-2022-20657
Vulnerability Description
The vulnerability arises from the processing of specific ARP traffic, potentially splitting the Flexible PIC Concentrator (FPC) in a virtual chassis upon PFE restart.
Affected Systems and Versions
Juniper Networks Junos OS versions prior to 21.3R2 on the EX4300 switch are impacted by this vulnerability.
Exploitation Mechanism
An unauthenticated attacker in the local broadcast domain can flood the system with specific ARP traffic, triggering a PFEMAN watchdog timeout.
Mitigation and Prevention
To address CVE-2022-20657:
Immediate Steps to Take
- Apply the following updated software releases: 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.
Long-Term Security Practices
Regularly update Junos OS to the latest patched versions and monitor for any unusual traffic patterns or disruptions.
Patching and Updates
Ensure timely application of vendor-released patches and follow best practices for network security.