Affected: AcademySoftwareFoundation openexr

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.3.2 through 3.3.0, there is a heap-based buffer overflow during a write operation when decompressing ZIPS-packed deep scan-line EXR files with a maliciously forged chunk header. This is fixed in version 3.3.3.

Affected: PyPI: OpenEXR

### Summary

The OpenEXRCore code is vulnerable to a heap-based buffer overflow during a write operation when decompressing ZIPS-packed deep scan-line EXR files with a maliciously forged chunk header.

### Details When parsing `STORAGE_DEEP_SCANLINE` chunks from an EXR file, the following code (from `src/lib/OpenEXRCore/chunk.c`) is used to extract the chunk information:

```cpp

if (part->storage_mode == EXR_STORAGE_DEEP_SCANLINE) // SNIP... cinfo->sample_count_data_offset = dataoff; cinfo->sample_count_table_size = (uint64_t) ddata[0]; cinfo->data_offset = dataoff + (uint64_t) ddata[0]; cinfo->packed_size = (uint64_t) ddata[1]; cinfo->unpacked_size = (uint64_t) ddata[2]; // SNIP... ```

By storing this information, the code that will later decompress and reconstruct the chunk bytes, will know how much space the uncompressed data will occupy.

This size is carried along in the chain of decoding/decompression until the `undo_zip_impl` function in `src/lib/OpenEXRCore/internal_zip.c`:

```cpp static exr_result_t undo_zip_impl ( exr_decode_pipeline_t* decode, const void* compressed_data, uint64_t comp_buf_size, void* uncompressed_data, uint64_t uncompressed_size, void* scratch_data, uint64_t scratch_size) { size_t actual_out_bytes; exr_result_t res;

if (scratch_size <…