A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" These issue are only triggered by traffic destined to the device. Transit traffic will not trigger these issues. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 16.1 version 16.1R1 and later versions; 16.2 version 16.2R1 and later versions; 17.1 version 17.1R1 and later versions; 17.2 version 17.2R1 and later versions; 17.3 versions prior to 17.3R3-S12; 17.4 version 17.4R1 and later versions; 18.1 versions prior to 18.1R3-S13; 18.2 version 18.2R1 and later versions; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.

This issue is not applicable to NFX NextGen Software. On NFX Series devices the use of Hard-coded Credentials in Juniper Networks Junos OS allows an attacker to take over any instance of an NFX deployment. This issue is only exploitable through administrative interfaces. This issue affects: Juniper Networks Junos OS versions prior to 19.1R1 on NFX Series. No other platforms besides NFX Series devices are affected.

A Use of Hard-coded Credentials vulnerability exists in the NFX250 Series for the vSRX Virtual Network Function (VNF) instance, which allows an attacker to take control of the vSRX VNF instance if they have the ability to access an administrative service (e.g. SSH) on the VNF, either locally, or through the network. This issue only affects the NFX250 Series vSRX VNF. No other products or platforms are affected. This issue is only applicable to environments where the vSRX VNF root password has not been configured. This issue affects the Juniper Networks NFX250 Network Services Platform vSRX VNF instance on versions prior to 19.2R1.

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.