A Heap-based Buffer Overflow vulnerability in the Network Services Daemon (NSD) of Juniper Networks Junos OS allows authenticated, low privileged, local attacker to cause a Denial of Service (DoS). On an SRX 5000 Series device, when executing a specific command repeatedly, memory is corrupted, which leads to a Flow Processing Daemon (flowd) crash. The NSD process has to be restarted to restore services.

If this issue occurs, it can be checked with the following command: user@host> request security policies check The following log message can also be observed: Error: policies are out of sync for PFE node<number>.fpc<number>.pic<number>. This issue affects: Juniper Networks Junos OS on SRX 5000 Series All versions earlier than 20.4R3-S6; 21.1 versions earlier than 21.1R3-S5; 21.2 versions earlier than 21.2R3-S4; 21.3 versions earlier than 21.3R3-S3; 21.4 versions earlier than 21.4R3-S3; 22.1 versions earlier than 22.1R3-S1; 22.2 versions earlier than 22.2R3; 22.3 versions earlier than 22.3R2.