CVE-2020-1683: On Juniper Networks Junos OS devices, a specific SNMP OID poll causes a memory leak which over time leads to a kernel crash (vmcore). Prior to the ker...

Description

On Juniper Networks Junos OS devices, a specific SNMP OID poll causes a memory leak which over time leads to a kernel crash (vmcore). Prior to the kernel crash other processes might be impacted, such as failure to establish SSH connection to the device. The administrator can monitor the output of the following command to check if there is memory leak caused by this issue: user@device> show system virtual-memory | match "pfe_ipc|kmem" pfe_ipc 147 5K - 164352 16,32,64,8192 <-- increasing vm.kmem_map_free: 127246336 <-- decreasing pfe_ipc 0 0K - 18598 32,8192 vm.kmem_map_free: 134582272 This issue affects Juniper Networks Junos OS: 17.4R3; 18.1 version 18.1R3-S5 and later versions prior to 18.1R3-S10; 18.2 version 18.2R3 and later versions prior to 18.2R3-S3; 18.2X75 version 18.2X75-D420, 18.2X75-D50 and later versions prior to 18.2X75-D430, 18.2X75-D53, 18.2X75-D60; 18.3 version 18.3R3 and later versions prior to 18.3R3-S2; 18.4 version 18.4R1-S4, 18.4R2 and later versions prior to 18.4R2-S5, 18.4R3-S1; 19.1 version 19.1R2 and later versions prior to 19.1R2-S2, 19.1R3; 19.2 version 19.2R1 and later versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2. This issue does not affect Juniper Networks Junos OS prior to 17.4R3.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.05%

59.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos	17.4	R3
Juniper	Junos	18.1	R3-S5
Juniper	Junos	18.2	R3
Juniper	Junos	18.2x75	—
Juniper	Junos	18.3	R3
Juniper	Junos	18.4	R1-S4
Juniper	Junos	19.1	R2
Juniper	Junos	19.2	R1
Juniper	Junos	19.3	—
Juniper	Junos	19.4	R1

References

https://kb.juniper.net/JSA11080Vendor Advisory
https://kb.juniper.net/JSA11080Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2020-1683?

On Juniper Networks Junos OS devices, a specific SNMP OID poll causes a memory leak which over time leads to a kernel crash (vmcore). Prior to the kernel crash other processes might be impacted, such as failure to establish SSH connection to the device. The administrator can monitor the output of the following command to check if there is memory leak caused by this issue: user@device> show system virtual-memory | match "pfe_ipc|kmem" pfe_ipc 147 5K - 164352 16,32,64,8192 <-- increasing vm.kmem_map_free: 127246336 <-- decreasing pfe_ipc 0 0K - 18598 32,8192 vm.kmem_map_free: 134582272 This issue affects Juniper Networks Junos OS: 17.4R3; 18.1 version 18.1R3-S5 and later versions prior to 18.1R3-S10; 18.2 version 18.2R3 and later versions prior to 18.2R3-S3; 18.2X75 version 18.2X75-D420, 18.2X75-D50 and later versions prior to 18.2X75-D430, 18.2X75-D53, 18.2X75-D60; 18.3 version 18.3R3 and later versions prior to 18.3R3-S2; 18.4 version 18.4R1-S4, 18.4R2 and later versions prior to 18.4R2-S5, 18.4R3-S1; 19.1 version 19.1R2 and later versions prior to 19.1R2-S2, 19.1R3; 19.2 version 19.2R1 and later versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2. This issue does not affect Juniper Networks Junos OS prior to 17.4R3.

How severe is CVE-2020-1683?

CVE-2020-1683 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.05% probability of exploitation in the next 30 days.

How do I fix CVE-2020-1683?

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.

How Strix Helps

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