An Improper Validation of Syntactic Correctness of Input vulnerability in the Juniper DHCP daemon (jdhcpd) of Juniper Networks Junos OS allows an adjacent unauthenticated attacker sending a malformed DHCP packet to cause a crash of jdhcpd and thereby a Denial of Service (DoS). If option-82 is configured in a DHCP snooping / -security scenario, jdhcpd crashes if a specific malformed DHCP request packet is received. The DHCP functionality is impacted while jdhcpd restarts, and continued exploitation of the vulnerability will lead to the unavailability of the DHCP service and thereby a sustained DoS. This issue affects Juniper Networks Junos OS 13.2 version 13.2R1 and later versions prior to 15.1R7-S11; 18.3 versions prior to 18.3R3-S6; 18.4 versions prior to 18.4R2-S9, 18.4R3-S10; 19.1 versions prior to 19.1R2-S3, 19.1R3-S7; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.3 versions prior to 19.3R2-S7, 19.3R3-S4; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R3-S3; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2-S1, 21.1R3; 21.2 versions prior to 21.2R1-S1, 21.2R2. This issue does not affect Juniper Networks Junos OS version 12.3R12 and prior versions.

Race condition in the Op command in Juniper Junos OS before 12.1X44-D55, 12.1X46 before 12.1X46-D40, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R11, 12.3X48 before 12.3X48-D20, 12.3X50 before 12.3X50-D50, 13.2 before 13.2R8, 13.2X51 before 13.2X51-D39, 13.2X52 before 13.2X52-D30, 13.3 before 13.3R7, 14.1 before 14.1R6, 14.1X53 before 14.1X53-D30, 14.2 before 14.2R4, 15.1 before 15.1F2 or 15.1R2, 15.1X49 before 15.1X49-D10 or 15.1X49-D20, and 16.1 before 16.1R1 allows remote authenticated users to gain privileges via the URL option.

Juniper Junos OS 12.1X44 before 12.1X44-D50, 12.1X46 before 12.1X46-D35, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R9, 12.3X48 before 12.3X48-D15, 13.2 before 13.2R7, 13.2X51 before 13.2X51-D35, 13.2X52 before 13.2X52-D25, 13.3 before 13.3R6, 14.1R3 before 14.1R3-S2, 14.1 before 14.1R4, 14.1X53 before 14.1X53-D12, 14.1X53 before 14.1X53-D16, 14.1X55 before 14.1X55-D25, 14.2 before 14.2R2, and 15.1 before 15.1R1 allows remote attackers to cause a denial of service (mbuf and connection consumption and restart) via a large number of requests that trigger a TCP connection to move to the LAST_ACK state when there is more data to send.