When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv4 packets who may then arbitrarily execute commands as root on the target device. This issue affects IPv4 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.

Specific IPv6 packets sent by clients processed by the Routing Engine (RE) are improperly handled. These IPv6 packets are designed to be blocked by the RE from egressing the RE. Instead, the RE allows these specific IPv6 packets to egress the RE, at which point a mbuf memory leak occurs within the Juniper Networks Junos OS device. This memory leak eventually leads to a kernel crash (vmcore), or the device hanging and requiring a power cycle to restore service, creating a Denial of Service (DoS) condition. During the time where mbufs are rising, yet not fully filled, some traffic from client devices may begin to be black holed. To be black holed, this traffic must match the condition where this traffic must be processed by the RE. Continued receipt and attempted egress of these specific IPv6 packets from the Routing Engine (RE) will create an extended Denial of Service (DoS) condition. Scenarios which have been observed are: 1. In a single chassis, single RE scenario, the device will hang without vmcore, or a vmcore may occur and then hang. In this scenario the device needs to be power cycled. 2. In a single chassis, dual RE scenario, the device master RE will fail over to the backup RE. In this scenario, the master and the backup REs need to be reset from time to time when they vmcore. There is no need to power cycle the device. 3. In a dual chassis, single RE scenario, the device will hang without vmcore, or a vmcore may occur and then hang. In this scenario, the two chassis' design relies upon some type of network level redundancy - VRRP, GRES, NSR, etc. - 3.a In a commanded switchover, where nonstop active routing (NSR) is enabled no session loss is observed. 4. In a dual chassis, dual chassis scenario, rely upon the RE to RE failover as stated in the second scenario. In the unlikely event that the device does not switch RE to RE gracefully, then the fallback position is to the network level services scenario in the third scenario. This issue affects: Juniper Networks Junos OS 16.1 versions prior to 16.1R7-S6; 16.1 version 16.1X70-D10 and later; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R1-S9, 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D50, 18.2X75-D410; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S6, 18.4R2-S2, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S2, 19.2R2. This issue does not affect releases prior to Junos OS 16.1R1.

When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv4 packets who may remotely take over the code execution of the JDHDCP process. This issue affect IPv4 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.

In a Point-to-Multipoint (P2MP) Label Switched Path (LSP) scenario, an uncontrolled resource consumption vulnerability in the Routing Protocol Daemon (RPD) in Juniper Networks Junos OS allows a specific SNMP request to trigger an infinite loop causing a high CPU usage Denial of Service (DoS) condition. This issue affects both SNMP over IPv4 and IPv6. This issue affects: Juniper Networks Junos OS: 12.3X48 versions prior to 12.3X48-D90; 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D238, 15.1X53-D592; 16.1 versions prior to 16.1R7-S5; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R3-S1; 17.2 versions prior to 17.2R3-S2; 17.3 versions prior to 17.3R3-S7; 17.4 versions prior to 17.4R2-S4, 17.4R3; 18.1 versions prior to 18.1R3-S5; 18.2 versions prior to 18.2R3; 18.2X75 versions prior to 18.2X75-D50; 18.3 versions prior to 18.3R2; 18.4 versions prior to 18.4R2; 19.1 versions prior to 19.1R2.

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.

An issue was discovered in Embedthis GoAhead before 4.0.1 and Appweb before 7.0.2. The server mishandles some HTTP request fields associated with time, which results in a NULL pointer dereference, as demonstrated by If-Modified-Since or If-Unmodified-Since with a month greater than 11.

named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted signature record for a DNAME record, related to db.c and resolver.c.

named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 does not properly handle DNAME records when parsing fetch reply messages, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a malformed packet to the rndc (aka control channel) interface, related to alist.c and sexpr.c.

Embedthis Appweb before 4.6.6 and 5.x before 5.2.1 allows remote attackers to cause a denial of service (NULL pointer dereference) via a Range header with an empty value, as demonstrated by "Range: x=,".

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.