CVE Vulnerabilities


Improper Restriction of Excessive Authentication Attempts

Published: Apr 10, 2019 | Modified: Feb 09, 2024
CVSS 3.x
CVSS 2.x

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.


The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks.

Affected Software

Name Vendor Start Version End Version
Junos Juniper 14.1x53 (including) 14.1x53-d49 (excluding)
Junos Juniper 15.1 (including) 15.1f6-s12 (excluding)
Junos Juniper 15.1x49 (including) 15.1x49-d160 (excluding)
Junos Juniper 15.1x53 (including) 15.1x53-d236 (excluding)
Junos Juniper 16.1 (including) 16.1r3-s10 (excluding)
Junos Juniper 16.1x65 (including) 16.1x65-d49 (excluding)
Junos Juniper 16.2 (including) 16.2r2-s7 (excluding)
Junos Juniper 17.1 (including) 17.1r2-s10 (excluding)
Junos Juniper 17.2 (including) 17.2r1-s8 (excluding)
Junos Juniper 17.3 (including) 17.3r3-s2 (excluding)
Junos Juniper 17.4 (including) 17.4r1-s6 (excluding)
Junos Juniper 18.1 (including) 18.1r2-s4 (excluding)
Junos Juniper 18.2 (including) 18.2r1-s5 (excluding)
Junos Juniper 18.2x75 (including) 18.2x75-d30 (excluding)
Junos Juniper 18.3 (including) 18.3r1-s1 (excluding)

Potential Mitigations

  • Common protection mechanisms include:

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

  • Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]