CVE-2020-1638 : Security Advisory and Response
Discover CVE-2020-1638, a high-severity vulnerability in Juniper Networks Junos OS and Junos OS Evolved, potentially leading to denial of service attacks through Flexible PIC Concentrator (FPC) restarts, impacting traffic flow. Learn about its impact, affected versions, and mitigation strategies.
This CVE involves a vulnerability in Juniper Networks Junos OS and Junos OS Evolved that can cause the Flexible PIC Concentrator (FPC) to restart when processing a specific IPv4 packet, potentially leading to a DoS attack.
Understanding CVE-2020-1638
This CVE affects certain versions of Junos OS and Junos OS Evolved, potentially enabling denial of service attacks through FPC restarts.
What is CVE-2020-1638?
The vulnerability allows an attacker to crash the FPC by continuously sending a specific IPv4 packet, disrupting all traffic passing through the FPC, impacting system availability.
The Impact of CVE-2020-1638
The vulnerability has a high severity level (CVSS base score of 7.5), with a significant availability impact. Successful exploitation can lead to extended Denial of Service conditions.
Technical Details of CVE-2020-1638
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The FPC may restart when processing a specific IPv4 packet, triggered only by packets reaching the device and successfully passing edge and control plane filtering.
Affected Systems and Versions
- Junos OS: Versions 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S1, and 19.4R2
- Junos OS Evolved: Versions 19.2-EVO, 19.3-EVO, 19.4-EVO prior to 19.4R2-EVO
Exploitation Mechanism
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
Mitigation and Prevention
Learn how to address and prevent the CVE-2020-1638 vulnerability.
Immediate Steps to Take
- Update affected systems to Junos OS versions 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S1, or 19.4R2, and Junos OS Evolved versions 19.4R2-EVO or later.
- Implement best security practices, including firewall filters and source address anti-spoofing, to reduce exposure risk.
Long-Term Security Practices
- Regularly monitor vendor security advisories for updates on vulnerabilities and patches.
- Conduct periodic security assessments to detect and address potential vulnerabilities.
Patching and Updates
- Apply software releases that address this specific vulnerability.