An Improper Check or Handling of Exceptional Conditions within the storm control feature of Juniper Networks Junos OS allows an attacker sending a high rate of traffic to cause a Denial of Service. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. Storm control monitors the level of applicable incoming traffic and compares it with the level specified. If the combined level of the applicable traffic exceeds the specified level, the switch drops packets for the controlled traffic types. This issue affects Juniper Networks Junos OS on QFX10002: All versions prior to 19.3R3-S7; 19.4 versions prior to 19.4R3-S11; 20.2 versions prior to 20.2R3-S6; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3; 21.4 versions prior to 21.4R2.