CVE-2021-0259 : Exploit Details and Defense Strategies
Discover the vulnerability in Juniper Networks Junos OS and OS Evolved on QFX5K Series switches, impacting network stability & potential DoS conditions. Learn about the impact, affected systems, and preventive measures.
A vulnerability in DDoS protection in Juniper Networks Junos OS and Junos OS Evolved on QFX5K Series switches can lead to network instability due to exceeding default protection thresholds.
Understanding CVE-2021-0259
This vulnerability affects Juniper Networks Junos OS and Junos OS Evolved on specific platforms and versions, potentially leading to a Denial of Service (DoS) condition.
What is CVE-2021-0259?
The issue arises from improper detection of DDoS violations, causing the underlay network to not process certain traffic and sustaining a DoS condition.
The Impact of CVE-2021-0259
Experiencing network instability and a potential DoS condition due to high traffic volume from specific, legitimate packets in a VXLAN scenario.
Technical Details of CVE-2021-0259
This section provides detailed information about the vulnerability, affected systems, and exploitation mechanisms.
Vulnerability Description
The vulnerability affects Junos OS and Junos OS Evolved, allowing attackers to disrupt the underlay network by exceeding DDoS protection thresholds.
Affected Systems and Versions
Juniper Networks Junos OS on QFX5K Series versions prior to 20.3R1-S2 and Junos OS Evolved on QFX5220 all versions are vulnerable.
Exploitation Mechanism
Although there are no known instances of malicious exploitation, attackers could trigger network instability by sending high volumes of specific traffic.
Mitigation and Prevention
Learn about the steps to mitigate the vulnerability and prevent potential network disruptions.
Immediate Steps to Take
Update to the latest software releases to address the vulnerability and ensure network stability.
Long-Term Security Practices
Regularly update and monitor your Juniper Networks devices to prevent security incidents and maintain network integrity.
Patching and Updates
Apply the following software releases to resolve the issue for Junos OS and Junos OS Evolved.
- Junos OS: 17.3R3-S11, 17.4R3-S5, 18.1R3-S13, 18.2R2-S8, 18.2R3-S8, 18.3R3-S5, 18.4R1-S8, 18.4R2-S6, 18.4R3-S6, 19.1R3-S4, 19.2R1-S6, 19.2R3-S2, 19.3R3-S2, 19.4R2-S4, 19.4R3-S1, 20.1R2, 20.2R2, 20.3R1-S2, 20.3R2, 20.4R1, and subsequent releases.
- Junos OS Evolved: 20.3R2-EVO, 20.4R1-EVO, and subsequent releases.