xdr-terraform-modules/base/nessus/instance_nessus_scanner/securitygroup-server.tf

# SG Summary - Server
#     Ingress: 
#       22 - sync from other security centers
#       443 - User access
#     Egress:  
#       25 - smtp
#       443 - updates
#       tcp/1243 - "Communicating with Log Correlation Engine" (unneeded in xdr)
#       tcp/8834-8835 - Communicating With Nessus - to vpc-scanners
resource "aws_security_group" "nessus_scanner" {
  name_prefix = "nessus_scanner"
  tags = merge( var.standard_tags, var.tags, { Name = "nessus_scanner" } )
  vpc_id      = var.vpc_id
  description = "Nessus Security Scanner"
}

#-----------------------------------------------------------------
# Inbound access
#-----------------------------------------------------------------
resource "aws_security_group_rule" "nessus_scanner_inbound_22" {
  security_group_id        = aws_security_group.nessus_scanner.id
  type                     = "ingress"
  cidr_blocks              = toset(concat(var.cidr_map["vpc-access"], var.cidr_map["vpc-private-services"]))
  from_port                = 22
  to_port                  = 22
  protocol                 = "tcp"
  description              = "Inbound 443 (from access)"
}

resource "aws_security_group_rule" "nessus_scanner_inbound_443" {
  security_group_id        = aws_security_group.nessus_scanner.id
  type                     = "ingress"
  cidr_blocks              = toset(concat(var.cidr_map["vpc-access"], var.cidr_map["vpc-private-services"]))
  from_port                = 443
  to_port                  = 443
  protocol                 = "tcp"
  description              = "Inbound 443 (from access)"
}

resource "aws_security_group_rule" "nessus_scanner_inbound_nessus" {
  security_group_id        = aws_security_group.nessus_scanner.id
  type                     = "ingress"
  cidr_blocks              = toset(concat(var.cidr_map["vpc-access"], var.cidr_map["vpc-private-services"]))
  from_port                = 8834
  to_port                  = 8835
  protocol                 = "tcp"
  description              = "Inbound Nessus"
}

resource "aws_security_group_rule" "nessus_scanner_inbound_scan_ourselves" {
  security_group_id        = aws_security_group.nessus_scanner.id
  source_security_group_id = aws_security_group.nessus_scanner.id
  type                     = "ingress"
  from_port                = -1
  to_port                  = -1
  protocol                 = "all"
  description              = "Inbound Scanning of Ourselves"
}

#-----------------------------------------------------------------
# Outbound access
#-----------------------------------------------------------------
resource "aws_security_group_rule" "nessus_scanner_outbound_all_ports" {
  security_group_id        = aws_security_group.nessus_scanner.id
  type                     = "egress"
  cidr_blocks              = [ "10.0.0.0/8" ]
  from_port                = -1
  to_port                  = -1
  protocol                 = "all"
  description              = "Outbound to All Ports"
}