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.

On the QFX3500 and QFX3600 platforms, the number of bytes collected from the RANDOM_INTERRUPT entropy source when the device boots up is insufficient, possibly leading to weak or duplicate SSH keys or self-signed SSL/TLS certificates. Entropy increases after the system has been up and running for some time, but immediately after boot, the entropy is very low. This issue only affects the QFX3500 and QFX3600 switches. No other Juniper Networks products or platforms are affected by this weak entropy vulnerability.