CVE-2020-1638

Junos OS & Junos OS Evolved: A specific IPv4 packet can lead to FPC restart.

Description

The FPC (Flexible PIC Concentrator) of Juniper Networks Junos OS and Junos OS Evolved may restart after processing a specific IPv4 packet. Only packets destined to the device itself, successfully reaching the RE through existing edge and control plane filtering, will be able to cause the FPC restart. When this issue occurs, all traffic via the FPC will be dropped. By continuously sending this specific IPv4 packet, an attacker can repeatedly crash the FPC, causing an extended Denial of Service (DoS) condition. This issue can only occur when processing a specific IPv4 packet. IPv6 packets cannot trigger this issue. This issue affects: Juniper Networks Junos OS on MX Series with MPC10E or MPC11E and PTX10001: 19.2 versions prior to 19.2R1-S4, 19.2R2; 19.3 versions prior to 19.3R2-S2, 19.3R3; 19.4 versions prior to 19.4R1-S1, 19.4R2. Juniper Networks Junos OS Evolved on on QFX5220, and PTX10003 series: 19.2-EVO versions; 19.3-EVO versions; 19.4-EVO versions prior to 19.4R2-EVO. This issue does not affect Junos OS versions prior to 19.2R1. This issue does not affect Junos OS Evolved versions prior to 19.2R1-EVO.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS: 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S1, 19.4R2, 20.1R1, and all subsequent releases. Junos OS Evolved: 19.4R2-EVO, 20.1R1-EVO, and all subsequent releases.

Workaround:

  • There is no workaround for this issue. Standard security best common practices such as limiting packet toward the RE only from trusted networks/host using firewall filter in combination with source address anti-spoofing should be applied to reduce the risk of exposure.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.39%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS Evolved
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11019 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-1638?
CVE-2020-1638 has been scored as a high severity vulnerability.
How to fix CVE-2020-1638?
To fix CVE-2020-1638: The following software releases have been updated to resolve this specific issue: Junos OS: 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S1, 19.4R2, 20.1R1, and all subsequent releases. Junos OS Evolved: 19.4R2-EVO, 20.1R1-EVO, and all subsequent releases.
Is CVE-2020-1638 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2020-1638 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-1638?
CVE-2020-1638 affects Juniper Networks Junos OS, Juniper Networks Junos OS, Juniper Networks Junos OS Evolved, Juniper Networks Junos OS Evolved.
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