Ruby before 2.4.2, 2.3.5, and 2.2.8 is vulnerable to a malicious format string which contains a precious specifier (*) with a huge minus value. Such situation can lead to a buffer overrun, resulting in a heap memory corruption or an information disclosure from the heap.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:HI:NA:H9.1/CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HInput Validation