Tornado before 3.2.2 sends arbitrary responses that contain a fixed CSRF token and may be sent with HTTP compression, which makes it easier for remote attackers to conduct a BREACH attack and determine this token via a series of crafted requests.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:HI:NA:N6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N