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+# AWS - Federation Abuse
+
+{{#include ../../../banners/hacktricks-training.md}}
+
+## SAML
+
+For info about SAML please check:
+
+{{#ref}}
+https://book.hacktricks.xyz/pentesting-web/saml-attacks
+{{#endref}}
+
+In order to configure an **Identity Federation through SAML** you just need to provide a **name** and the **metadata XML** containing all the SAML configuration (**endpoints**, **certificate** with public key)
+
+## OIDC - Github Actions Abuse
+
+In order to add a github action as Identity provider:
+
+1. For _Provider type_, select **OpenID Connect**.
+2. For _Provider URL_, enter `https://token.actions.githubusercontent.com`
+3. Click on _Get thumbprint_ to get the thumbprint of the provider
+4. For _Audience_, enter `sts.amazonaws.com`
+5. Create a **new role** with the **permissions** the github action need and a **trust policy** that trust the provider like:
+   - ```json
+     {
+       "Version": "2012-10-17",
+       "Statement": [
+         {
+           "Effect": "Allow",
+           "Principal": {
+             "Federated": "arn:aws:iam::0123456789:oidc-provider/token.actions.githubusercontent.com"
+           },
+           "Action": "sts:AssumeRoleWithWebIdentity",
+           "Condition": {
+             "StringEquals": {
+               "token.actions.githubusercontent.com:sub": [
+                 "repo:ORG_OR_USER_NAME/REPOSITORY:pull_request",
+                 "repo:ORG_OR_USER_NAME/REPOSITORY:ref:refs/heads/main"
+               ],
+               "token.actions.githubusercontent.com:aud": "sts.amazonaws.com"
+             }
+           }
+         }
+       ]
+     }
+     ```
+6. Note in the previous policy how only a **branch** from **repository** of an **organization** was authorized with a specific **trigger**.
+7. The **ARN** of the **role** the github action is going to be able to **impersonate** is going to be the "secret" the github action needs to know, so **store** it inside a **secret** inside an **environment**.
+8. Finally use a github action to configure the AWS creds to be used by the workflow:
+
+```yaml
+name: "test AWS Access"
+
+# The workflow should only trigger on pull requests to the main branch
+on:
+  pull_request:
+    branches:
+      - main
+
+# Required to get the ID Token that will be used for OIDC
+permissions:
+  id-token: write
+  contents: read # needed for private repos to checkout
+
+jobs:
+  aws:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Configure AWS Credentials
+        uses: aws-actions/configure-aws-credentials@v1
+        with:
+          aws-region: eu-west-1
+          role-to-assume:${{ secrets.READ_ROLE }}
+          role-session-name: OIDCSession
+
+      - run: aws sts get-caller-identity
+        shell: bash
+```
+
+## OIDC - EKS Abuse
+
+```bash
+# Crate an EKS cluster (~10min)
+eksctl create cluster --name demo --fargate
+```
+
+```bash
+# Create an Identity Provider for an EKS cluster
+eksctl utils associate-iam-oidc-provider --cluster Testing --approve
+```
+
+It's possible to generate **OIDC providers** in an **EKS** cluster simply by setting the **OIDC URL** of the cluster as a **new Open ID Identity provider**. This is a common default policy:
+
+```json
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Effect": "Allow",
+      "Principal": {
+        "Federated": "arn:aws:iam::123456789098:oidc-provider/oidc.eks.us-east-1.amazonaws.com/id/20C159CDF6F2349B68846BEC03BE031B"
+      },
+      "Action": "sts:AssumeRoleWithWebIdentity",
+      "Condition": {
+        "StringEquals": {
+          "oidc.eks.us-east-1.amazonaws.com/id/20C159CDF6F2349B68846BEC03BE031B:aud": "sts.amazonaws.com"
+        }
+      }
+    }
+  ]
+}
+```
+
+This policy is correctly indicating than **only** the **EKS cluster** with **id** `20C159CDF6F2349B68846BEC03BE031B` can assume the role. However, it's not indicting which service account can assume it, which means that A**NY service account with a web identity token** is going to be **able to assume** the role.
+
+In order to specify **which service account should be able to assume the role,** it's needed to specify a **condition** where the **service account name is specified**, such as:
+
+```bash
+"oidc.eks.region-code.amazonaws.com/id/20C159CDF6F2349B68846BEC03BE031B:sub": "system:serviceaccount:default:my-service-account",
+```
+
+## References
+
+- [https://www.eliasbrange.dev/posts/secure-aws-deploys-from-github-actions-with-oidc/](https://www.eliasbrange.dev/posts/secure-aws-deploys-from-github-actions-with-oidc/)
+
+{{#include ../../../banners/hacktricks-training.md}}