该问题通常是由于Lambda函数位于具有私有子网和公有子网的VPC中引起的。如果您希望Lambda函数能够从同一AWS账户中的EC2访问，则必须将Lambda函数放置在具有公有子网和NAT网关的VPC中。

以下是一个示例CloudFormation模板，用于创建具有公有子网和NAT网关的VPC：

---
AWSTemplateFormatVersion: '2010-09-09'

Resources:

  VPC:
    Type: 'AWS::EC2::VPC'
    Properties:
      CidrBlock: '10.0.0.0/16'
      EnableDnsSupport: true
      EnableDnsHostnames: true
      InstanceTenancy: default
      Tags:
        - Key: 'Name'
          Value: 'MyVPC'

  PublicSubnet1:
    Type: 'AWS::EC2::Subnet'
    Properties:
      AvailabilityZone: !Select [ 0, !GetAZs '' ]
      VpcId: !Ref VPC
      CidrBlock: '10.0.1.0/24'
      Tags:
        - Key: 'Name'
          Value: 'PublicSubnet1'

  PublicSubnet2:
    Type: 'AWS::EC2::Subnet'
    Properties:
      AvailabilityZone: !Select [ 1, !GetAZs '' ]
      VpcId: !Ref VPC
      CidrBlock: '10.0.2.0/24'
      Tags:
        - Key: 'Name'
          Value: 'PublicSubnet2'

  InternetGateway:
    Type: 'AWS::EC2::InternetGateway'

  VPCGatewayAttachment:
    Type: 'AWS::EC2::VPCGatewayAttachment'
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway

  PublicRouteTable:
    Type: 'AWS::EC2::RouteTable'
    Properties:
      VpcId: !Ref VPC
      Tags:
        - Key: 'Name'
          Value: 'PublicRouteTable'

  PublicRoute:
    Type: 'AWS::EC2::Route'
    DependsOn: VPCGatewayAttachment
    Properties:
      RouteTableId: !Ref PublicRouteTable
      DestinationCidrBlock: '0.0.0.0/0'
      GatewayId: !Ref InternetGateway

  PublicSubnet1RouteTableAssociation:
    Type: 'AWS::EC2::