The gdImageScaleTwoPass function in gd_interpolation.c in the GD Graphics Library (aka libgd) before 2.2.0, as used in PHP before 5.6.12, uses inconsistent allocate and free approaches, which allows remote attackers to cause a denial of service (memory consumption) via a crafted call, as demonstrated by a call to the PHP imagescale function.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:H7.5/CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H