Usermin 0.980 through 1.x before 1.660 allows uconfig_save.cgi sig_file_free remote code execution because it uses the two argument (not three argument) form of Perl open.
Exploitability
AV:NAC:LPR:LUI:NScope
S:CImpact
C:HI:HA:H9.9/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HOther