CVE-2020-1680: On Juniper Networks MX Series with MS-MIC or MS-MPC card configured with NAT64 configuration, receipt of a malformed IPv6 packet may crash the MS-PIC ...

Description

On Juniper Networks MX Series with MS-MIC or MS-MPC card configured with NAT64 configuration, receipt of a malformed IPv6 packet may crash the MS-PIC component on MS-MIC or MS-MPC. This issue occurs when a multiservice card is translating the malformed IPv6 packet to IPv4 packet. An unauthenticated attacker can continuously send crafted IPv6 packets through the device causing repetitive MS-PIC process crashes, resulting in an extended Denial of Service condition. This issue affects Juniper Networks Junos OS on MX Series: 15.1 versions prior to 15.1R7-S7; 15.1X53 versions prior to 15.1X53-D593; 16.1 versions prior to 16.1R7-S8; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S11, 17.4R3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D53, 18.2X75-D65; 18.3 versions prior to 18.3R2-S4, 18.3R3; 18.4 versions prior to 18.4R2-S5, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

1.30%

66.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos	15.1	—
Juniper	Junos	15.1x53	—
Juniper	Junos	16.1	—
Juniper	Junos	17.2	—
Juniper	Junos	17.3	R3-S5
Juniper	Junos	17.4	—
Juniper	Junos	18.1	—
Juniper	Junos	18.2	—
Juniper	Junos	18.2x75	—
Juniper	Junos	18.3	—
Juniper	Junos	18.4	—
Juniper	Junos	19.1	—
Juniper	Junos	19.2	—
Juniper	Junos	19.3	—

References

https://kb.juniper.net/JSA11077Vendor Advisory
https://kb.juniper.net/JSA11077Vendor Advisory

Timeline

Published: Oct 16, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-1680?

On Juniper Networks MX Series with MS-MIC or MS-MPC card configured with NAT64 configuration, receipt of a malformed IPv6 packet may crash the MS-PIC component on MS-MIC or MS-MPC. This issue occurs when a multiservice card is translating the malformed IPv6 packet to IPv4 packet. An unauthenticated attacker can continuously send crafted IPv6 packets through the device causing repetitive MS-PIC process crashes, resulting in an extended Denial of Service condition. This issue affects Juniper Networks Junos OS on MX Series: 15.1 versions prior to 15.1R7-S7; 15.1X53 versions prior to 15.1X53-D593; 16.1 versions prior to 16.1R7-S8; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S11, 17.4R3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D53, 18.2X75-D65; 18.3 versions prior to 18.3R2-S4, 18.3R3; 18.4 versions prior to 18.4R2-S5, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2.

How severe is CVE-2020-1680?

CVE-2020-1680 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.30% probability of exploitation in the next 30 days.

How do I fix CVE-2020-1680?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.