CVE-2023-36835 : What You Need to Know
Learn about CVE-2023-36835, an Improper Check for Unusual Conditions vulnerability in Juniper Networks Junos OS on QFX10000 Series, allowing DoS attacks and impacting traffic. Find out the impacted systems and how to prevent it.
A detailed overview of CVE-2023-36835 focusing on the impact, technical details, and mitigation strategies.
Understanding CVE-2023-36835
Exploring the vulnerability in Junos OS on QFX10000 Series that can lead to a Denial of Service (DoS) attack.
What is CVE-2023-36835?
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network-based attacker to cause a DoS. This issue arises when a valid IP packet routed over a VXLAN tunnel triggers a PFE wedge condition, impacting traffic until system reboot.
The Impact of CVE-2023-36835
The vulnerability affects Juniper Networks Junos OS on QFX10000 Series versions 20.3 and later, 20.4 prior to 20.4R3-S5, 21.1 prior to 21.1R3-S5, 21.2 prior to 21.2R3-S5, 21.3 prior to 21.3R3-S4, 21.4 prior to 21.4R3-S1, 22.1 prior to 22.1R3, 22.2 prior to 22.2R2, and 22.3 prior to 22.3R1-S2, 22.3R2.
Technical Details of CVE-2023-36835
Insights into the vulnerability description, affected systems and versions, and exploitation mechanism.
Vulnerability Description
The vulnerability allows attackers to exploit the PFE of Junos OS, leading to a DoS attack when specific IP packets are routed over a VXLAN tunnel.
Affected Systems and Versions
Juniper Networks Junos OS on QFX10000 Series versions 20.3 and later are impacted, along with subsequent versions up to 22.3R2.
Exploitation Mechanism
The vulnerability can be exploited through network-based attacks that trigger a PFE wedge condition due to a specific IP packet routing scenario.
Mitigation and Prevention
Guidelines on the immediate steps to take, long-term security practices, and necessary patching and updates.
Immediate Steps to Take
Upgrade to the recommended software releases to address the vulnerability and prevent potential exploitation of the PFE in Junos OS.
Long-Term Security Practices
Implement robust network security measures, monitor for any unusual network activity, and stay informed about potential vulnerabilities in Juniper products.
Patching and Updates
Install the specified Junos OS software releases, including versions 20.4R3-S5, 21.1R3-S5, 21.2R3-S5, 21.3R3-S4, 21.4R3-S1, 22.1R3, 22.2R2, 22.3R1-S2, 22.3R2, 22.4R1, and subsequent updates.