AWS - Federation Abuse

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SAML

Kwa maelezo kuhusu SAML tafadhali angalia:

SAML Attacks - HackTricks

Ili kuunda Identity Federation kupitia SAML unahitaji tu kutoa jina na metadata XML inayojumuisha usanidi wote wa SAML (endpoints, cheti chenye funguo za umma)

OIDC - Github Actions Abuse

Ili kuongeza hatua ya github kama mtoa kitambulisho:

  1. Kwa Aina ya Mtoa, chagua OpenID Connect.
  2. Kwa URL ya Mtoa, ingiza https://token.actions.githubusercontent.com
  3. Bonyeza Pata thumbprint ili kupata thumbprint ya mtoa
  4. Kwa Audience, ingiza sts.amazonaws.com
  5. Unda jukumu jipya lenye idhini zinazohitajika na hatua ya github na sera ya kuamini inayomwamini mtoa kama:

{ "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. Kumbuka katika sera iliyopita jinsi **tawi** moja tu kutoka **hifadhi** ya **shirika** lilihitajika kwa **trigger** maalum.
7. **ARN** ya **jukumu** ambalo hatua ya github itakuwa na uwezo wa **kujifanya** ni "siri" ambayo hatua ya github inahitaji kujua, hivyo **hifadhi** ndani ya **siri** ndani ya **mazingira**.
8. Hatimaye tumia hatua ya github kusanidi AWS creds zitakazotumika na workflow:

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

Crate an EKS cluster (~10min)

eksctl create cluster --name demo --fargate

Create an Identity Provider for an EKS cluster

eksctl utils associate-iam-oidc-provider --cluster Testing --approve

Inawezekana kuunda **OIDC providers** katika **EKS** cluster kwa kuweka **OIDC URL** ya cluster kama **mtoa kitambulisho kipya cha Open ID**. Hii ni sera ya kawaida ya default:

{ "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" } } } ] }

Sera hii inabainisha kwa usahihi kwamba **tu** **EKS cluster** yenye **id** `20C159CDF6F2349B68846BEC03BE031B` inaweza kuchukua jukumu. Hata hivyo, haionyeshi ni akaunti gani ya huduma inaweza kuchukua jukumu hilo, ambayo ina maana kwamba **AKAUNTI YOYOTE YA HUDUMA yenye tokeni ya utambulisho wa wavuti** itakuwa **na uwezo wa kuchukua** jukumu hilo.

Ili kubainisha **ni akaunti gani ya huduma inapaswa kuwa na uwezo wa kuchukua jukumu,** inahitajika kubainisha **hali** ambapo **jina la akaunti ya huduma linabainishwa**, kama:

"oidc.eks.region-code.amazonaws.com/id/20C159CDF6F2349B68846BEC03BE031B:sub": "system:serviceaccount:default:my-service-account",