CVE-2019-0039

CVE-2019-0039 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 8.1. 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-307.

Key facts

Description

If REST API is enabled, the Junos OS login credentials are vulnerable to brute force attacks. The high default connection limit of the REST API may allow an attacker to brute-force passwords using advanced scripting techniques. Additionally, administrators who do not enforce a strong password policy can increase the likelihood of success from brute force attacks. Affected releases are Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D49; 15.1 versions prior to 15.1F6-S12, 15.1R7-S3; 15.1X49 versions prior to 15.1X49-D160; 15.1X53 versions prior to 15.1X53-D236, 15.1X53-D495, 15.1X53-D591, 15.1X53-D69; 16.1 versions prior to 16.1R3-S10, 16.1R4-S12, 16.1R6-S6, 16.1R7-S3; 16.1X65 versions prior to 16.1X65-D49; 16.2 versions prior to 16.2R2-S7; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R3-S1; 17.3 versions prior to 17.3R3-S2; 17.4 versions prior to 17.4R1-S6, 17.4R2-S2; 18.1 versions prior to 18.1R2-S4, 18.1R3-S1; 18.2 versions prior to 18.2R1-S5; 18.2X75 versions prior to 18.2X75-D30; 18.3 versions prior to 18.3R1-S1.

Frequently asked questions

What is CVE-2019-0039?
If REST API is enabled, the Junos OS login credentials are vulnerable to brute force attacks. The high default connection limit of the REST API may allow an attacker to brute-force passwords using advanced scripting techniques. Additionally, administrators who do not enforce a strong password policy can increase the likelihood of success from brute force attacks. Affected releases are Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D49; 15.1 versions prior to 15.1F6-S12, 15.1R7-S3; 15.1X49 versions prior to 15.1X49-D160; 15.1X53 versions prior to 15.1X53-D236, 15.1X53-D495, 15.1X53-D591, 15.1X53-D69; 16.1 versions prior to 16.1R3-S10, 16.1R4-S12, 16.1R6-S6, 16.1R7-S3; 16.1X65 versions prior to 16.1X65-D49; 16.2 versions prior to 16.2R2-S7; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R3-S1; 17.3 versions prior to 17.3R3-S2; 17.4 versions prior to 17.4R1-S6, 17.4R2-S2; 18.1 versions prior to 18.1R2-S4, 18.1R3-S1; 18.2 versions prior to 18.2R1-S5; 18.2X75 versions prior to 18.2X75-D30; 18.3 versions prior to 18.3R1-S1.
How severe is CVE-2019-0039?
CVE-2019-0039 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-0039 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-0039?
CVE-2019-0039 affects Juniper Junos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-0039?
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-2019-0039 published?
CVE-2019-0039 was published on 2019-04-10 and last updated on 2026-06-17.

References

Affected products (1)

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