CVE-2020-1632

CVE-2020-1632 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-755.

Key facts

Description

In a certain condition, receipt of a specific BGP UPDATE message might cause Juniper Networks Junos OS and Junos OS Evolved devices to advertise an invalid BGP UPDATE message to other peers, causing the other peers to terminate the established BGP session, creating a Denial of Service (DoS) condition. For example, Router A sends a specific BGP UPDATE to Router B, causing Router B to send an invalid BGP UPDATE message to Router C, resulting in termination of the BGP session between Router B and Router C. This issue might occur when there is at least a single BGP session established on the device that does not support 4 Byte AS extension (RFC 4893). Repeated receipt of the same BGP UPDATE can result in an extended DoS condition. This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S2; 17.2 versions prior to 17.2R1-S9, 17.2R2-S8, 17.2R3-S3; 17.2X75 versions prior to 17.2X75-D105, 17.2X75-D110, 17.2X75-D44; 17.3 versions prior to 17.3R2-S5, 17.3R3-S7; 17.4 versions prior to 17.4R2-S8, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R2-S6, 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D51, 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R3; 18.4 version 18.4R2 and later versions; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S2, 19.2R2. This issue does not affect Juniper Networks Junos OS prior to 16.1R1. This issue affects Juniper Networks Junos OS Evolved prior to 19.2R2-EVO.

Frequently asked questions

What is CVE-2020-1632?
In a certain condition, receipt of a specific BGP UPDATE message might cause Juniper Networks Junos OS and Junos OS Evolved devices to advertise an invalid BGP UPDATE message to other peers, causing the other peers to terminate the established BGP session, creating a Denial of Service (DoS) condition. For example, Router A sends a specific BGP UPDATE to Router B, causing Router B to send an invalid BGP UPDATE message to Router C, resulting in termination of the BGP session between Router B and Router C. This issue might occur when there is at least a single BGP session established on the device that does not support 4 Byte AS extension (RFC 4893). Repeated receipt of the same BGP UPDATE can result in an extended DoS condition. This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S2; 17.2 versions prior to 17.2R1-S9, 17.2R2-S8, 17.2R3-S3; 17.2X75 versions prior to 17.2X75-D105, 17.2X75-D110, 17.2X75-D44; 17.3 versions prior to 17.3R2-S5, 17.3R3-S7; 17.4 versions prior to 17.4R2-S8, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R2-S6, 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D51, 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R3; 18.4 version 18.4R2 and later versions; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S2, 19.2R2. This issue does not affect Juniper Networks Junos OS prior to 16.1R1. This issue affects Juniper Networks Junos OS Evolved prior to 19.2R2-EVO.
How severe is CVE-2020-1632?
CVE-2020-1632 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-1632 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-1632?
CVE-2020-1632 primarily affects Juniper Junos. In total, 121 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-1632?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-1632 published?
CVE-2020-1632 was published on 2020-04-15 and last updated on 2026-06-17.

References

Affected products (121)

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