An improper authorization weakness in Juniper Networks Junos OS allows a local authenticated attacker to bypass regular security controls to access the Junos Device Manager (JDM) application and take control of the system. This issue affects: Juniper Networks Junos OS versions prior to 18.2R1, 18.2X75-D5.

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.

In a Dynamic Host Configuration Protocol version 6 (DHCPv6) environment, the jdhcpd daemon may crash and restart upon receipt of certain DHCPv6 solicit messages received from a DHCPv6 client. By continuously sending the same crafted packet, an attacker can repeatedly crash the jdhcpd process causing a sustained Denial of Service (DoS) to both IPv4 and IPv6 clients. Affected releases are Juniper Networks Junos OS: 15.1 versions prior to 15.1F6-S12, 15.1R7-S3; 15.1X49 versions prior to 15.1X49-D171, 15.1X49-D180; 15.1X53 versions prior to 15.1X53-D236, 15.1X53-D496; 16.1 versions prior to 16.1R3-S10, 16.1R7-S4; 16.2 versions prior to 16.2R2-S8; 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-S3; 17.4 versions prior to 17.4R1-S6, 17.4R2-S3; 18.1 versions prior to 18.1R2-S4, 18.1R3-S2; 18.2 versions prior to 18.2R2; 18.2X75 versions prior to 18.2X75-D30; 18.3 versions prior to 18.3R1-S2. This issue does not affect Junos OS releases prior to 15.1.

A vulnerability in the Network Address Translation - Protocol Translation (NAT-PT) feature of Junos OS on SRX series devices may allow a certain valid IPv6 packet to crash the flowd daemon. Repeated crashes of the flowd daemon can result in an extended denial of service condition for the SRX device. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D72; 12.3X48 versions prior to 12.3X48-D55; 15.1X49 versions prior to 15.1X49-D90.

Memory leak in Juniper JUNOS Packet Forwarding Engine (PFE) allows remote attackers to cause a denial of service (memory exhaustion and device reboot) via certain IPv6 packets.

TCP, when using a large Window Size, makes it easier for remote attackers to guess sequence numbers and cause a denial of service (connection loss) to persistent TCP connections by repeatedly injecting a TCP RST packet, especially in protocols that use long-lived connections, such as BGP.