CVE-2020-1686

Junos OS: Kernel crash (vmcore) upon receipt of a malformed IPv6 packet.

HIGH

7.5

CVSS Score

Published: October 16, 2020 at 08:31 PM UTC

Updated: June 17, 2026 at 03:02 AM UTC

1 product affected across 1 vendorJunos

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Severity

HIGH7.5

Exploit prediction

EPSS 1%

Description

On Juniper Networks Junos OS devices, receipt of a malformed IPv6 packet may cause the system to crash and restart (vmcore). This issue can be trigged by a malformed IPv6 packet destined to the Routing Engine. An attacker can repeatedly send the offending packet resulting in an extended Denial of Service condition. Only IPv6 packets can trigger this issue. IPv4 packets cannot trigger this issue. This issue affects Juniper Networks Junos OS 18.4 versions prior to 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2. This issue does not affect Juniper Networks Junos OS prior to 18.4R1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

18.4 ≤ v < 18.4R2-S4, 18.4R3-S119.1 ≤ v < 19.1R2-S1, 19.1R319.2 ≤ v < 19.2R1-S5, 19.2R219.3 ≤ v < 19.3R2-S4, 19.3R319.4 ≤ v < 19.4R1-S3, 19.4R218.4 18.4 r1 18.4 r1-s1 18.4 r1-s2 18.4 r1-s5 18.4 r1-s6 18.4 r2 18.4 r2-s1 18.4 r2-s2 18.4 r2-s3 18.4 r3 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.1 r1-s4 19.1 r2 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2 19.3 r2-s3 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2

Vendor states this is fixed in 18.4R1 (unaffected)

Affected range stops below 18.4R2-S4, 18.4R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R2-S1, 19.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R1-S5, 19.2R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R2-S4, 19.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.4R1-S3, 19.4R2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://kb.juniper.net/JSA11083

References (1)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://kb.juniper.net/JSA11083

CVSS

7.5HIGHjuniper

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-415NVD-CWE-noinfo

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