# GCP - Cloud Functions Unauthenticated Enum

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## Cloud Functions

Maggiore informazione sulle Cloud Functions può essere trovata in:

{{#ref}}
../gcp-services/gcp-cloud-functions-enum.md
{{#endref}}

### Brute Force URls

**Brute Force il formato dell'URL**:

- `https://<region>-<project-gcp-name>.cloudfunctions.net/<func_name>`

È più facile se conosci i nomi dei progetti.

Controlla questa pagina per alcuni strumenti per eseguire questo brute force:

{{#ref}}
./
{{#endref}}

### Enumerare le Cloud Functions Aperte

Con il seguente codice [preso da qui](https://gitlab.com/gitlab-com/gl-security/security-operations/gl-redteam/gcp_misc/-/blob/master/find_open_functions.sh) puoi trovare le Cloud Functions che permettono invocazioni non autenticate.
```bash
#!/bin/bash

############################
# Run this tool to find Cloud Functions that permit unauthenticated invocations
# anywhere in your GCP organization.
# Enjoy!
############################

for proj in $(gcloud projects list --format="get(projectId)"); do
echo "[*] scraping project $proj"

enabled=$(gcloud services list --project "$proj" | grep "Cloud Functions API")

if [ -z "$enabled" ]; then
continue
fi


for func_region in $(gcloud functions list --quiet --project "$proj" --format="value[separator=','](NAME,REGION)"); do
# drop substring from first occurence of "," to end of string.
func="${func_region%%,*}"
# drop substring from start of string up to last occurence of ","
region="${func_region##*,}"
ACL="$(gcloud functions get-iam-policy "$func" --project "$proj" --region "$region")"

all_users="$(echo "$ACL" | grep allUsers)"
all_auth="$(echo "$ACL" | grep allAuthenticatedUsers)"

if [ -z "$all_users" ]
then
:
else
echo "[!] Open to all users: $proj: $func"
fi

if [ -z "$all_auth" ]
then
:
else
echo "[!] Open to all authenticated users: $proj: $func"
fi
done
done
```
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