static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
#ifdef MOV_EXPORT_ALL_METADATA
    char tmp_key[5];
#endif
    char str[1024], key2[16], language[4] = {0};
    const char *key = NULL;
    uint16_t str_size, langcode = 0;
    uint32_t data_type = 0;
    int (*parse)(MOVContext*, AVIOContext*, unsigned, const char*) = NULL;

    switch (atom.type) {
    case MKTAG(0xa9,'n','a','m'): key = "title";     break;
    case MKTAG(0xa9,'a','u','t'):
    case MKTAG(0xa9,'A','R','T'): key = "artist";    break;
    case MKTAG( 'a','A','R','T'): key = "album_artist";    break;
    case MKTAG(0xa9,'w','r','t'): key = "composer";  break;
    case MKTAG( 'c','p','r','t'):
    case MKTAG(0xa9,'c','p','y'): key = "copyright"; break;
    case MKTAG(0xa9,'g','r','p'): key = "grouping"; break;
    case MKTAG(0xa9,'l','y','r'): key = "lyrics"; break;
    case MKTAG(0xa9,'c','m','t'):
    case MKTAG(0xa9,'i','n','f'): key = "comment";   break;
    case MKTAG(0xa9,'a','l','b'): key = "album";     break;
    case MKTAG(0xa9,'d','a','y'): key = "date";      break;
    case MKTAG(0xa9,'g','e','n'): key = "genre";     break;
    case MKTAG( 'g','n','r','e'): key = "genre";
        parse = mov_metadata_gnre; break;
    case MKTAG(0xa9,'t','o','o'):
    case MKTAG(0xa9,'s','w','r'): key = "encoder";   break;
    case MKTAG(0xa9,'e','n','c'): key = "encoder";   break;
    case MKTAG( 'd','e','s','c'): key = "description";break;
    case MKTAG( 'l','d','e','s'): key = "synopsis";  break;
    case MKTAG( 't','v','s','h'): key = "show";      break;
    case MKTAG( 't','v','e','n'): key = "episode_id";break;
    case MKTAG( 't','v','n','n'): key = "network";   break;
    case MKTAG( 't','r','k','n'): key = "track";
        parse = mov_metadata_track_or_disc_number; break;
    case MKTAG( 'd','i','s','k'): key = "disc";
        parse = mov_metadata_track_or_disc_number; break;
    case MKTAG( 't','v','e','s'): key = "episode_sort";
        parse = mov_metadata_int8_bypass_padding; break;
    case MKTAG( 't','v','s','n'): key = "season_number";
        parse = mov_metadata_int8_bypass_padding; break;
    case MKTAG( 's','t','i','k'): key = "media_type";
        parse = mov_metadata_int8_no_padding; break;
    case MKTAG( 'h','d','v','d'): key = "hd_video";
        parse = mov_metadata_int8_no_padding; break;
    case MKTAG( 'p','g','a','p'): key = "gapless_playback";
        parse = mov_metadata_int8_no_padding; break;
    }

    if (c->itunes_metadata && atom.size > 8) {
        int data_size = avio_rb32(pb);
        int tag = avio_rl32(pb);
        if (tag == MKTAG('d','a','t','a')) {
            data_type = avio_rb32(pb); // type
            avio_rb32(pb); // unknown
            str_size = data_size - 16;
            atom.size -= 16;
        } else return 0;
    } else if (atom.size > 4 && key && !c->itunes_metadata) {
        str_size = avio_rb16(pb); // string length
        langcode = avio_rb16(pb);
        ff_mov_lang_to_iso639(langcode, language);
        atom.size -= 4;
    } else
        str_size = atom.size;

#ifdef MOV_EXPORT_ALL_METADATA
    if (!key) {
        snprintf(tmp_key, 5, "%.4s", (char*)&atom.type);
        key = tmp_key;
    }
#endif

    if (!key)
        return 0;
    if (atom.size < 0)
        return AVERROR_INVALIDDATA;

    str_size = FFMIN3(sizeof(str)-1, str_size, atom.size);

    if (parse)
        parse(c, pb, str_size, key);
    else {
        if (data_type == 3 || (data_type == 0 && (langcode < 0x400 || langcode == 0x7fff))) { // MAC Encoded
            mov_read_mac_string(c, pb, str_size, str, sizeof(str));
        } else {
            avio_read(pb, str, str_size);
            str[str_size] = 0;
        }
        av_dict_set(&c->fc->metadata, key, str, 0);
        if (*language && strcmp(language, "und")) {
            snprintf(key2, sizeof(key2), "%s-%s", key, language);
            av_dict_set(&c->fc->metadata, key2, str, 0);
        }
    }
    av_dlog(c->fc, "lang \"%3s\" ", language);
    av_dlog(c->fc, "tag \"%s\" value \"%s\" atom \"%.4s\" %d %"PRId64"\n",
            key, str, (char*)&atom.type, str_size, atom.size);

    return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.