Vulnerability Monitor

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CVE-2020-1633

Due to a new NDP proxy feature for EVPN leaf nodes introduced in Junos OS 17.4, crafted NDPv6 packets could transit a Junos device configured as a Broadband Network Gateway (BNG) and reach the EVPN leaf node, causing a stale MAC address entry. This could cause legitimate traffic to be discarded, leading to a Denial of Service (DoS) condition. This issue only affects Junos OS 17.4 and later releases. Prior releases do not support this feature and are unaffected by this vulnerability. This issue only affects IPv6. IPv4 ARP proxy is unaffected by this vulnerability. This issue affects Juniper Networks Junos OS: 17.4 versions prior to 17.4R2-S9, 17.4R3 on MX Series; 18.1 versions prior to 18.1R3-S9 on MX Series; 18.2 versions prior to 18.2R2-S7, 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3 on MX Series; 18.4 versions prior to 18.4R1-S5, 18.4R2-S2, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S4, 19.1R2 on MX Series; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.4, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 16 products from juniper, from juniper, from juniper and 13 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2020-04-09T23:15:12.983

Last Modified

2026-06-17T03:02:02.800

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.4 (HIGH)

CVSSv2 Vector

AV:A/AC:L/Au:N/C:N/I:N/A:P

Access Vector: ADJACENT_NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

6.5

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-20
Type: Primary
NVD-CWE-noinfo

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2x75	Yes
Operating System	juniper	junos	18.2x75	Yes
Operating System	juniper	junos	18.2x75	Yes
Operating System	juniper	junos	18.2x75	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Hardware	juniper	mx10	-	No
Hardware	juniper	mx10000	-	No
Hardware	juniper	mx10003	-	No
Hardware	juniper	mx104	-	No
Hardware	juniper	mx150	-	No
Hardware	juniper	mx2008	-	No
Hardware	juniper	mx2010	-	No
Hardware	juniper	mx2020	-	No
Hardware	juniper	mx204	-	No
Hardware	juniper	mx240	-	No
Hardware	juniper	mx40	-	No
Hardware	juniper	mx480	-	No
Hardware	juniper	mx5	-	No
Hardware	juniper	mx80	-	No
Hardware	juniper	mx960	-	No

References

https://kb.juniper.net/JSA11012 Vendor Advisory ([email protected])
https://kb.juniper.net/JSA11012 Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.