private boolean skipToPropertyInfoSection(InputStream stream, byte[] header) throws IOException, TikaException {
        // The offset is stored in the header from 0x20 onwards
        long offsetToSection = EndianUtils.getLongLE(header, 0x20);

        // Bounds check the offset. Some files seem to use a different format,
        // and the offset isn't available at 0x20. Until we can work out how
        // to find the offset in those files, skip them if detected
        if (offsetToSection > 0xa00000l) {
            // Header should never be more than 10mb into the file, something is wrong
            offsetToSection = 0;
        }

        // Work out how far to skip, and bounds check
        long toSkip = offsetToSection - header.length;
        if (offsetToSection == 0) {
            return false;
        }
        IOUtils.skipFully(stream, toSkip);

        return true;
    }
Grab the offset, then skip there
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-cad-module/src/main/java/org/apache/tika/parser/dwg/DWGParser.java