A Protection Mechanism Failure vulnerability in RPD (routing protocol daemon) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause established IS-IS adjacencies to go down by sending a spoofed hello PDU leading to a Denial of Service (DoS) condition. Continued receipted of these spoofed PDUs will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS All versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R2-EVO; 21.1 versions prior to 21.1R2-EVO.

An Improper Check for Unusual or Exceptional Conditions vulnerability combined with Improper Handling of Exceptional Conditions in Juniper Networks Junos OS on QFX Series and PTX Series allows an unauthenticated network based attacker to cause increased FPC CPU utilization by sending specific IP packets which are being VXLAN encapsulated leading to a partial Denial of Service (DoS). Continued receipted of these specific traffic will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on QFX Series: All versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R2-S3, 19.4R3-S1; 20.1 versions prior to 20.1R2, 20.1R3; 20.2 versions prior to 20.2R2, 20.2R3; 20.3 versions prior to 20.3R1-S1, 20.3R2. Juniper Networks Junos OS on PTX Series: All versions prior to 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-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.

An improper privilege management vulnerability in the Juniper Networks Junos OS and Junos OS Evolved command-line interpreter (CLI) allows a low-privileged user to overwrite local files as root, possibly leading to a system integrity issue or Denial of Service (DoS). Depending on the files overwritten, exploitation of this vulnerability could lead to a sustained Denial of Service (DoS) condition, requiring manual user intervention to recover. Systems are only vulnerable if jdhcpd is running, which can be confirmed via the 'show system processes' command. For example: root@host# run show system processes extensive | match dhcp 26537 root -16 0 97568K 13692K RUN 0 0:01 3.71% jdhcpd This issue affects: Juniper Networks Junos OS: All versions, including the following supported releases: 15.1 versions prior to 15.1R7-S10; 17.4 versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 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-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S6; 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. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO; All versions of 21.1-EVO.

A local privilege escalation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged user to cause the Juniper DHCP daemon (jdhcpd) process to crash, resulting in a Denial of Service (DoS), or execute arbitrary commands as root. Continued processing of malicious input will repeatedly crash the system and sustain the Denial of Service (DoS) condition. Systems are only vulnerable if jdhcpd is running, which can be confirmed via the 'show system processes' command. For example: root@host# run show system processes extensive | match dhcp 26537 root -16 0 97568K 13692K RUN 0 0:01 3.71% jdhcpd This issue affects: Juniper Networks Junos OS: All versions, including the following supported releases: 15.1 versions prior to 15.1R7-S10; 17.4 versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 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-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S6; 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. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO; All versions of 21.1-EVO.

An Out Of Bounds (OOB) access vulnerability in the handling of responses by a Juniper Agile License (JAL) Client in Juniper Networks Junos OS and Junos OS Evolved, configured in Network Mode (to use Juniper Agile License Manager) may allow an attacker to cause a partial Denial of Service (DoS), or lead to remote code execution (RCE). The vulnerability exists in the packet parsing logic on the client that processes the response from the server using a custom protocol. An attacker with control of a JAL License Manager, or with access to the local broadcast domain, may be able to spoof a new JAL License Manager and/or craft a response to the Junos OS License Client, leading to exploitation of this vulnerability. This issue only affects Junos systems configured in Network Mode. Systems that are configured in Standalone Mode (the default mode of operation for all systems) are not vulnerable to this issue. This issue affects: Juniper Networks Junos OS: 19.2 versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 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 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS Evolved: version 20.1R1-EVO and later versions, prior to 21.2R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R1.

An Improper Privilege Management vulnerability in the gRPC framework, used by the Juniper Extension Toolkit (JET) API on Juniper Networks Junos OS and Junos OS Evolved, allows a network-based, low-privileged authenticated attacker to perform operations as root, leading to complete compromise of the targeted system. The issue is caused by the JET service daemon (jsd) process authenticating the user, then passing configuration operations directly to the management daemon (mgd) process, which runs as root. This issue affects Juniper Networks Junos OS: 18.4 versions prior to 18.4R1-S8, 18.4R2-S8, 18.4R3-S8; 19.1 versions prior to 19.1R2-S3, 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2. This issue does not affect Juniper Networks Junos OS versions prior to 18.4R1. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-EVO; 21.1-EVO versions prior to 21.1R2-EVO.

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" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 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 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.

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.

An Out-of-bounds Read vulnerability in the processing of specially crafted LLDP frames by the Layer 2 Control Protocol Daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved may allow an attacker to cause a Denial of Service (DoS), or may lead to remote code execution (RCE). Continued receipt and processing of these frames, sent from the local broadcast domain, will repeatedly crash the l2cpd process and sustain the Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S18; 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13, 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2. Juniper Networks Junos OS Evolved versions prior to 20.4R2-EVO.

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.