providers/oauth2: fix CVE-2024-21637 (#8104)

Signed-off-by: Jens Langhammer <jens@goauthentik.io>
This commit is contained in:
Jens L 2024-01-09 18:14:12 +01:00 committed by GitHub
parent 9ecabe4629
commit 6649f7ab72
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5 changed files with 73 additions and 4 deletions

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@ -87,6 +87,25 @@ class TestAuthorize(OAuthTestCase):
)
OAuthAuthorizationParams.from_request(request)
def test_blocked_redirect_uri(self):
"""test missing/invalid redirect URI"""
OAuth2Provider.objects.create(
name=generate_id(),
client_id="test",
authorization_flow=create_test_flow(),
redirect_uris="data:local.invalid",
)
with self.assertRaises(RedirectUriError):
request = self.factory.get(
"/",
data={
"response_type": "code",
"client_id": "test",
"redirect_uri": "data:localhost",
},
)
OAuthAuthorizationParams.from_request(request)
def test_invalid_redirect_uri_empty(self):
"""test missing/invalid redirect URI"""
provider = OAuth2Provider.objects.create(

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@ -76,6 +76,7 @@ PLAN_CONTEXT_PARAMS = "goauthentik.io/providers/oauth2/params"
SESSION_KEY_LAST_LOGIN_UID = "authentik/providers/oauth2/last_login_uid"
ALLOWED_PROMPT_PARAMS = {PROMPT_NONE, PROMPT_CONSENT, PROMPT_LOGIN}
FORBIDDEN_URI_SCHEMES = {"javascript", "data", "vbscript"}
@dataclass(slots=True)
@ -179,6 +180,10 @@ class OAuthAuthorizationParams:
self.check_scope(github_compat)
self.check_nonce()
self.check_code_challenge()
if self.request:
raise AuthorizeError(
self.redirect_uri, "request_not_supported", self.grant_type, self.state
)
def check_redirect_uri(self):
"""Redirect URI validation."""
@ -216,10 +221,9 @@ class OAuthAuthorizationParams:
redirect_uri_expected=allowed_redirect_urls,
)
raise RedirectUriError(self.redirect_uri, allowed_redirect_urls)
if self.request:
raise AuthorizeError(
self.redirect_uri, "request_not_supported", self.grant_type, self.state
)
# Check against forbidden schemes
if urlparse(self.redirect_uri).scheme in FORBIDDEN_URI_SCHEMES:
raise RedirectUriError(self.redirect_uri, allowed_redirect_urls)
def check_scope(self, github_compat=False):
"""Ensure openid scope is set in Hybrid flows, or when requesting an id_token"""

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@ -6,6 +6,7 @@ from hashlib import sha256
from re import error as RegexError
from re import fullmatch
from typing import Any, Optional
from urllib.parse import urlparse
from django.http import HttpRequest, HttpResponse
from django.utils import timezone
@ -55,6 +56,7 @@ from authentik.providers.oauth2.models import (
RefreshToken,
)
from authentik.providers.oauth2.utils import TokenResponse, cors_allow, extract_client_auth
from authentik.providers.oauth2.views.authorize import FORBIDDEN_URI_SCHEMES
from authentik.sources.oauth.models import OAuthSource
from authentik.stages.password.stage import PLAN_CONTEXT_METHOD, PLAN_CONTEXT_METHOD_ARGS
@ -206,6 +208,10 @@ class TokenParams:
).from_http(request)
raise TokenError("invalid_client")
# Check against forbidden schemes
if urlparse(self.redirect_uri).scheme in FORBIDDEN_URI_SCHEMES:
raise TokenError("invalid_request")
self.authorization_code = AuthorizationCode.objects.filter(code=raw_code).first()
if not self.authorization_code:
LOGGER.warning("Code does not exist", code=raw_code)

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@ -0,0 +1,39 @@
# CVE-2024-21637
_Reported by [@lauritzh](https://github.com/lauritzh)_
## XSS in Authentik via JavaScript-URI as Redirect URI and form_post Response Mode
### Summary
Given an OAuth2 provider configured with allowed redirect URIs set to `*` or `.*`, an attacker can send an OAuth Authorization request using `response_mode=form_post` and setting `redirect_uri` to a malicious URI, to capture authentik's session token.
### Patches
authentik 2023.8.6 and 2023.10.6 fix this issue.
### Impact
The impact depends on the attack scenario. In the following I will describe the two scenario that were identified for Authentik.
#### Redirect URI Misconfiguration
While advising that this may cause security issues, Authentik generally allows wildcards as Redirect URI. Therefore, using a wildcard-only effectively allowing arbitrary URLS is possible misconfiguration that may be present in real-world instances.
In such cases, unauthenticated and unprivileged attackers can perform the above described actions.
### User with (only) App Administration Permissions
A more likely scenario is an administrative user (e.g. a normal developer) having only permissions to manage applications.
This relatively user could use the described attacks to perform a privilege escalation.
### Workaround
It is recommended to upgrade to the patched version of authentik. If not possible, ensure that OAuth2 providers do not use a wildcard (`*` or `.*`) value as allowed redirect URI setting. (This is _not_ exploitable if part of the redirect URI has a wildcard, for example `https://foo-.*\.bar\.com`)
### For more information
If you have any questions or comments about this advisory:
- Email us at [security@goauthentik.io](mailto:security@goauthentik.io)

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@ -408,6 +408,7 @@ const docsSidebar = {
},
items: [
"security/policy",
"security/CVE-2024-21637",
"security/CVE-2023-48228",
"security/GHSA-rjvp-29xq-f62w",
"security/CVE-2023-39522",