CVE-2020-1689

CVE-2020-1689 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 6.5. 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-400.

Key facts

Description

On Juniper Networks EX4300-MP Series, EX4600 Series and QFX5K Series deployed in a Virtual Chassis configuration, receipt of a stream of specific layer 2 frames can cause high CPU load, which could lead to traffic interruption. This issue does not occur when the device is deployed in Stand Alone configuration. The offending layer 2 frame packets can originate only from within the broadcast domain where the device is connected. This issue affects Juniper Networks Junos OS on EX4300-MP Series, EX4600 Series and QFX5K Series: 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R3-S2; 19.2 versions prior to 19.2R1-S5, 19.2R3; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S1, 19.4R3; 20.1 versions prior to 20.1R1-S3, 20.1R2.

Frequently asked questions

What is CVE-2020-1689?
On Juniper Networks EX4300-MP Series, EX4600 Series and QFX5K Series deployed in a Virtual Chassis configuration, receipt of a stream of specific layer 2 frames can cause high CPU load, which could lead to traffic interruption. This issue does not occur when the device is deployed in Stand Alone configuration. The offending layer 2 frame packets can originate only from within the broadcast domain where the device is connected. This issue affects Juniper Networks Junos OS on EX4300-MP Series, EX4600 Series and QFX5K Series: 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R3-S2; 19.2 versions prior to 19.2R1-S5, 19.2R3; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S1, 19.4R3; 20.1 versions prior to 20.1R1-S3, 20.1R2.
How severe is CVE-2020-1689?
CVE-2020-1689 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-1689 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-1689?
CVE-2020-1689 primarily affects Juniper Junos. In total, 130 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-1689?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-1689 published?
CVE-2020-1689 was published on 2020-10-16 and last updated on 2026-06-17.

References

Affected products (130)

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