> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/appsec-rules/iac-security/public-exposure/appsec-gcp-3.md).

# GCP Firewall rule allows all traffic on RDP port (3389) misconfiguration detected in code

## Rule Details

|                        |                                      |
| ---------------------- | ------------------------------------ |
| Cortex AppSec Rule ID  | APPSEC\_GCP\_3                       |
| Category - Subcategory | Public Exposure - Sensitive Ports    |
| Provider               | GCP                                  |
| Severity               | LOW                                  |
| Framework              | Terraform, Terraform Plan            |
| Mapped CSPM/KSPM Rule  | 34175634-0e4a-4e9d-9c77-0c75390b8bdc |

## Impact

Firewall rules setup fine grained allow/deny traffic policies to and from a virtual machine (VM). Enabled rules are always enforced, and help protecting instances from unwanted traffic. Firewall rules are defined at the network level, and only apply to the network where they are created. Every VPC functions as a distributed firewall. While firewall rules are defined at the network level, connections are allowed or denied on a per-instance basis. A default network is pre-populated with firewall rules that allow incoming traffic to instances. The *default-allow-rdp* rule permits ingress connections on TCP port 3389 from any source to any instance in the network. We recommend you restrict or remove the *default-allow-rdp* rule when you no longer need it.

## How to Fix

*Resource:* google\_compute\_firewall

* *Arguments:* deny.

## The deny block supports: *protocol* (Required) The IP protocol to which this rule applies. The protocol type is required when creating a firewall rule. This value can either be one of the following well known protocol strings (tcp, udp, icmp, esp, ah, sctp, ipip), or the IP protocol number. *ports* (Optional) An optional list of ports to which this rule applies. This field is only applicable for UDP or TCP protocol. Each entry must be either an integer or a range. If not specified, this rule applies to connections through any port. Example inputs include: \["22"], \["80","443"], and \["12345-12349"]. \[source,go]

resource "google\_compute\_firewall" "default" { name = "test-firewall" network = google\_compute\_network.default.name

allow { protocol = "icmp" }

deny { protocol = "tcp" ports = \["3389"] }

## ", }


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