When sFlow is enabled and it monitors a packet forwarded via ECMP, a buffer management vulnerability in the dcpfe process of Juniper Networks Junos OS on QFX10K Series systems allows an attacker to cause the Packet Forwarding Engine (PFE) to crash and restart by sending specific genuine packets to the device, resulting in a Denial of Service (DoS) condition. The dcpfe process tries to copy more data into a smaller buffer, which overflows and corrupts the buffer, causing a crash of the dcpfe process. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on QFX10K Series: All versions prior to 19.4R3-S9; 20.2 versions prior to 20.2R3-S6; 20.3 versions prior to 20.3R3-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-S2; 21.4 versions prior to 21.4R2-S2, 21.4R3; 22.1 versions prior to 22.1R2; 22.2 versions prior to 22.2R1-S2, 22.2R2.