CVE-2020-1667

Junos OS: MX Series: Services card might restart due to a race condition when DNS filtering is enabled.

HIGH

8.3

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

HIGH8.3

Exploit prediction

EPSS 0.7%

Description

When DNS filtering is enabled on Juniper Networks Junos MX Series with one of the following cards MS-PIC, MS-MIC or MS-MPC, an incoming stream of packets processed by the Multiservices PIC Management Daemon (mspmand) process might be bypassed due to a race condition. Due to this vulnerability, mspmand process, responsible for managing "URL Filtering service", can crash, causing the Services PIC to restart. While the Services PIC is restarting, all PIC services including DNS filtering service (DNS sink holing) will be bypassed until the Services PIC completes its boot process. This issue affects Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S8; 18.3 versions prior to 18.3R3-S1; 18.4 versions prior to 18.4R3; 19.1 versions prior to 19.1R3; 19.2 versions prior to 19.2R2; 19.3 versions prior to 19.3R3. This issue does not affect Juniper Networks Junos OS 17.4, 18.1, and 18.2.

Affected

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

Junos · Juniper Networks

95%

17.3 ≤ v < 17.3R3-S818.3 ≤ v < 18.3R3-S118.4 ≤ v < 18.4R319.1 ≤ v < 19.1R319.2 ≤ v < 19.2R219.3 ≤ v < 19.3R317.3 17.3 r1-s1 17.3 r2 17.3 r2-s1 17.3 r2-s2 17.3 r2-s3 17.3 r2-s4 17.3 r2-s5 17.3 r3 17.3 r3-s1 17.3 r3-s2 17.3 r3-s3 17.3 r3-s4 17.3 r3-s7 18.3 18.3 r1 18.3 r1-s1 18.3 r1-s2 18.3 r1-s3 18.3 r1-s5 18.3 r1-s6 18.3 r2 18.3 r2-s1 18.3 r2-s2 18.3 r2-s3 18.3 r3 18.4 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 r2-s4 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.1 r1-s4 19.1 r2 19.1 r2-s1 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2

Affected range stops below 17.3R3-S8, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 17.4 (unaffected)

Vendor states this is fixed in 18.1 (unaffected)

Vendor states this is fixed in 18.2 (unaffected)

Affected range stops below 18.3R3-S1, so it looks safe — our inference, not a vendor statement

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

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

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

Affected range stops below 19.3R3, 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

References (2)

x_refsource_MISCVendor Advisory

Source: [email protected]

https://kb.juniper.net/

Vendor Advisory

Source: [email protected]

https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11064&cat=MX_SERIES&actp=LIST

CVSS

8.3HIGHjuniper

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

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-362

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