A Use After Free vulnerability in the Layer 2 Address Learning Manager (l2alm) of Juniper Networks Junos OS on QFX Series allows an adjacent attacker to cause the Packet Forwarding Engine to crash and restart, leading to a Denial of Service (DoS). The PFE may crash when a lot of MAC learning and aging happens, but due to a Race Condition (Concurrent Execution using Shared Resource with Improper Synchronization) that is outside the attackers direct control. This issue affects: Juniper Networks Junos OS versions prior to 19.4R3-S10 on QFX Series; 20.2 versions prior to 20.2R3-S7 on QFX Series; 20.3 versions prior to 20.3R3-S6 on QFX Series; 20.4 versions prior to 20.4R3-S5 on QFX Series; 21.1 versions prior to 21.1R3-S4 on QFX Series; 21.2 versions prior to 21.2R3-S3 on QFX Series; 21.3 versions prior to 21.3R3-S3 on QFX Series; 21.4 versions prior to 21.4R3 on QFX Series; 22.1 versions prior to 22.1R3 on QFX Series; 22.2 versions prior to 22.2R2 on QFX Series.

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.

When user-defined ARP Policer is configured and applied on one or more Aggregated Ethernet (AE) interface units, a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability between the Device Control Daemon (DCD) and firewall process (dfwd) daemons of Juniper Networks Junos OS allows an attacker to bypass the user-defined ARP Policer. In this particular case the User ARP policer is replaced with default ARP policer. To review the desired ARP Policers and actual state one can run the command "show interfaces <> extensive" and review the output. See further details below. An example output is: show interfaces extensive | match policer Policer: Input: __default_arp_policer__ <<< incorrect if user ARP Policer was applied on an AE interface and the default ARP Policer is displayed Policer: Input: jtac-arp-ae5.317-inet-arp <<< correct if user ARP Policer was applied on an AE interface For all platforms, except SRX Series: This issue affects Juniper Networks Junos OS: All versions 5.6R1 and all later versions prior to 18.4 versions prior to 18.4R2-S9, 18.4R3-S9 with the exception of 15.1 versions 15.1R7-S10 and later versions; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3-S2; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2; This issue does not affect Juniper Networks Junos OS versions prior to 5.6R1. On SRX Series this issue affects Juniper Networks Junos OS: 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.4 versions prior to 19.4R3-S4; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3-S2; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. This issue does not affect 18.4 versions prior to 18.4R1 on SRX Series. This issue does not affect Junos OS Evolved.

A vulnerability in the BGP FlowSpec implementation may cause a Juniper Networks Junos OS device to terminate an established BGP session upon receiving a specific BGP FlowSpec advertisement. The BGP NOTIFICATION message that terminates an established BGP session is sent toward the peer device that originally sent the specific BGP FlowSpec advertisement. This specific BGP FlowSpec advertisement received from a BGP peer might get propagated from a Junos OS device running the fixed release to another device that is vulnerable causing BGP session termination downstream. This issue affects IPv4 and IPv6 BGP FlowSpec deployment. This issue affects Juniper Networks Junos OS: 12.3; 12.3X48 on SRX Series; 14.1X53 on EX and QFX Series; 15.1 versions prior to 15.1R7-S5; 15.1F versions prior to 15.1F6-S13; 15.1X49 versions prior to 15.1X49-D180 on SRX Series; 15.1X53 versions prior to 15.1X53-D238 on QFX5200/QFX5110; 15.1X53 versions prior to 15.1X53-D497 on NFX Series; 15.1X53 versions prior to 15.1X53-D592 on EX2300/EX3400; 16.1 versions prior to 16.1R7-S7; 17.1 versions prior to 17.1R2-S12, 17.1R3; 17.2 versions prior to 17.2R2-S7, 17.2R3; 17.2X75 versions prior to 17.2X75-D102, 17.2X75-D110, 17.2X75-D44; 17.3 versions prior to 17.3R2-S5, 17.3R3-S5; 17.4 versions prior to 17.4R1-S8, 17.4R2; 18.1 versions prior to 18.1R2-S4, 18.1R3; 18.2X75 versions prior to 18.2X75-D20.

Insufficient Cross-Site Scripting (XSS) protection in J-Web may potentially allow a remote attacker to inject web script or HTML, hijack the target user's J-Web session and perform administrative actions on the Junos device as the targeted user. This issue affects Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S15; 12.3X48 versions prior to 12.3X48-D86, 12.3X48-D90 on SRX Series; 14.1X53 versions prior to 14.1X53-D51 on EX and QFX Series; 15.1F6 versions prior to 15.1F6-S13; 15.1 versions prior to 15.1R7-S5; 15.1X49 versions prior to 15.1X49-D181, 15.1X49-D190 on SRX Series; 15.1X53 versions prior to 15.1X53-D238 on QFX5200/QFX5110 Series; 15.1X53 versions prior to 15.1X53-D592 on EX2300/EX3400 Series; 16.1 versions prior to 16.1R4-S13, 16.1R7-S5; 16.2 versions prior to 16.2R2-S10; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R1-S9, 17.2R3-S2; 17.3 versions prior to 17.3R2-S5, 17.3R3-S5; 17.4 versions prior to 17.4R2-S6, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R2-S5, 18.2R3; 18.3 versions prior to 18.3R1-S6, 18.3R2-S1, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2; 19.1 versions prior to 19.1R1-S2, 19.1R2.