AP4_VisualSampleEntry::ReadFields in Core/Ap4SampleEntry.cpp in Bento4 1.5.0-617 uses incorrect character data types, which causes a stack-based buffer underflow and out-of-bounds write, leading to denial of service (application crash) or possibly unspecified other impact.
https://github.com/axiomatic-systems/Bento4/commit/03d1222ab9c2ce779cdf01bdb96cdd69cbdcfeda