The pcnet_rdra_addr function in hw/net/pcnet.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by setting the (1) receive or (2) transmit descriptor ring length to 0.
Exploitability
AV:LAC:LPR:HUI:NScope
S:UImpact
C:NI:NA:H4.4/CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H