static int bson_append_string_base( bson *b, const char *name,
                                    const char *value, int len, bson_type type ) {

    int sl = len + 1;
    if ( bson_check_string( b, ( const char * )value, sl - 1 ) == BSON_ERROR )
        return BSON_ERROR;
    if ( bson_append_estart( b, type, name, 4 + sl ) == BSON_ERROR ) {
        return BSON_ERROR;
    }
    bson_append32( b , &sl );
    bson_append( b , value , sl - 1 );
    bson_append( b , "\0" , 1 );
    return BSON_OK;
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.