Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffer overflows, which can be exploited to bypass veriexec restrictions on Junos OS. A stack-based overflow is present in the handling of environment variables when connecting via the telnet client to remote telnet servers. This issue only affects the telnet client — accessible from the CLI or shell — in Junos OS. Inbound telnet services are not affected by this issue. This issue affects: Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S13; 12.3X48 versions prior to 12.3X48-D80; 14.1X53 versions prior to 14.1X53-D130, 14.1X53-D49; 15.1 versions prior to 15.1F6-S12, 15.1R7-S4; 15.1X49 versions prior to 15.1X49-D170; 15.1X53 versions prior to 15.1X53-D237, 15.1X53-D496, 15.1X53-D591, 15.1X53-D69; 16.1 versions prior to 16.1R3-S11, 16.1R7-S4; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R2-S7, 17.2R3-S1; 17.3 versions prior to 17.3R3-S4; 17.4 versions prior to 17.4R1-S6, 17.4R2-S3, 17.4R3; 18.1 versions prior to 18.1R2-S4, 18.1R3-S3; 18.2 versions prior to 18.2R1-S5, 18.2R2-S2, 18.2R3; 18.2X75 versions prior to 18.2X75-D40; 18.3 versions prior to 18.3R1-S3, 18.3R2; 18.4 versions prior to 18.4R1-S2, 18.4R2.

On Junos devices with the BGP graceful restart helper mode enabled or the BGP graceful restart mechanism enabled, a certain sequence of 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. Repeated crashes of the RPD process can cause 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-S3; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R3; 17.2X75 versions prior to 17.2X75-D105; 17.3 versions prior to 17.3R3-S2; 17.4 versions prior to 17.4R1-S7, 17.4R2-S2, 17.4R3; 18.1 versions prior to 18.1R3-S2; 18.2 versions prior to 18.2R2; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D30; 18.3 versions prior to 18.3R1-S4, 18.3R2. Junos OS releases prior to 16.1R1 are not affected.

On EX4300 Series switches with TCAM optimization enabled, incoming multicast traffic matches an implicit loopback filter rule first, since it has high priority. This rule is meant for reserved multicast addresses 224.0.0.x, but incorrectly matches on 224.x.x.x. Due to this bug, when a firewall filter is applied on the loopback interface, other firewall filters might stop working for multicast traffic. The command 'show firewall filter' can be used to confirm whether the filter is working. This issue only affects the EX4300 switch. No other products or platforms are affected by this vulnerability. This issue affects: Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D51, 14.1X53-D115 on EX4300 Series; 17.1 versions prior to 17.1R3 on EX4300 Series; 17.2 versions prior to 17.2R3-S2 on EX4300 Series; 17.3 versions prior to 17.3R3-S3 on EX4300 Series; 17.4 versions prior to 17.4R2-S5, 17.4R3 on EX4300 Series; 18.1 versions prior to 18.1R3-S1 on EX4300 Series; 18.2 versions prior to 18.2R2 on EX4300 Series; 18.3 versions prior to 18.3R2 on EX4300 Series.

A vulnerability in the pfe-chassisd Chassis Manager (CMLC) daemon of Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) to the EX4300 when specific valid broadcast packets create a broadcast storm condition when received on the me0 interface of the EX4300 Series device. A reboot of the device is required to restore service. Continued receipt of these valid broadcast packets will create a sustained Denial of Service (DoS) against the device. Affected releases are Juniper Networks Junos OS: 16.1 versions above and including 16.1R1 prior to 16.1R7-S5; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R3; 17.3 versions prior to 17.3R3-S2; 17.4 versions prior to 17.4R2; 18.1 versions prior to 18.1R3; 18.2 versions prior to 18.2R2.

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.

The Junos OS kernel crashes after processing a specific incoming packet to the out of band management interface (such as fxp0, me0, em0, vme0) destined for another address. By continuously sending this type of packet, an attacker can repeatedly crash the kernel causing a sustained Denial of Service. Affected releases are Juniper Networks Junos OS: 17.2 versions prior to 17.2R1-S7, 17.2R3; 17.3 versions prior to 17.3R3-S3; 17.4 versions prior to 17.4R1-S4, 17.4R2; 17.2X75 versions prior to 17.2X75-D110; 18.1 versions prior to 18.1R2.

Receipt of a malformed packet on MX Series devices with dynamic vlan configuration can trigger an uncontrolled recursion loop in the Broadband Edge subscriber management daemon (bbe-smgd), and lead to high CPU usage and a crash of the bbe-smgd service. Repeated receipt of the same packet can result in an extended denial of service condition for the device. Affected releases are Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S1; 16.2 versions prior to 16.2R2-S7; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R3; 17.3 versions prior to 17.3R3-S1; 17.4 versions prior to 17.4R2; 18.1 versions prior to 18.1R3; 18.2 versions prior to 18.2R2.

An issue was discovered in Embedthis GoAhead before 4.0.1 and Appweb before 7.0.2. An HTTP POST request with a specially crafted "Host" header field may cause a NULL pointer dereference and thus cause a denial of service, as demonstrated by the lack of a trailing ']' character in an IPv6 address.