On Junos devices with the BGP graceful restart helper mode enabled or the BGP graceful restart mechanism enabled, a BGP session restart on a remote peer that has the graceful restart mechanism enabled may cause the local routing protocol daemon (RPD) process to crash and restart. By simulating a specific BGP session restart, an attacker can repeatedly crash the RPD process causing prolonged denial of service (DoS). Graceful restart helper mode for BGP is enabled by default. No other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS: 16.1 versions prior to 16.1R7; 16.1X65 versions prior to 16.1X65-D48; 16.2 versions prior to 16.2R2-S8; 17.1 versions prior to 17.1R2-S7, 17.1R3; 17.2 versions prior to 17.2R1-S7, 17.2R3; 17.2X75 versions prior to 17.2X75-D92, 17.2X75-D102, 17.2X75-D110; 17.3 versions prior to 17.3R2-S2, 17.3R3; 17.4 versions prior to 17.4R1-S4, 17.4R2; 18.1 versions prior to 18.1R2. Junos OS releases prior to 16.1R1 are not affected.

A certain sequence of valid BGP or IPv6 BFD packets may trigger a stack based buffer overflow in the Junos OS Packet Forwarding Engine manager (FXPC) process on QFX5000 series, EX4300, EX4600 devices. This issue can result in a crash of the fxpc daemon or may potentially lead to remote code execution. Affected releases are Juniper Networks Junos OS on QFX 5000 series, EX4300, EX4600 are: 14.1X53; 15.1X53 versions prior to 15.1X53-D235; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R3; 17.3 versions prior to 17.3R3-S2, 17.3R4; 17.4 versions prior to 17.4R2-S1, 17.4R3; 18.1 versions prior to 18.1R3-S1, 18.1R4; 18.2 versions prior to 18.2R2; 18.2X75 versions prior to 18.2X75-D30; 18.3 versions prior to 18.3R2.

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.