An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rre.c allows out-of-bounds access via encodings.
Created libvncserver tracking bugs for this issue:
Affects: epel-7 [bug 1860338]
Affects: fedora-all [bug 1860339]
in libvncserver/rre.c's subrectEncode##bpp() rectangle encoder, there's a potential out-of-bounds read due to && operator order. The patch reverses the order. This flaw could potentially cause undefined behavior or a crash if the width (w) is incorrect.