GHSA-g6w6-r76c-28j7 BIT-nats-2022-24450 CVE-2022-24450 GO-2022-0307
Incorrect Authorization in NATS nats-server
- Severity
- 8.8 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 1.33%
- Chance of exploitation in the next 30 days. Higher than 71.08% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-863 Incorrect Authorization
- Fix
- Available
- 2 packages have a fixed version
Description
(This advisory is canonically https://advisories.nats.io/CVE/CVE-2022-24450.txt)
Problem Description
NATS nats-server through 2022-02-04 has Incorrect Access Control, with unchecked ability for clients to authorize into any account, because of a coding error in a long-extant experimental feature.
A client crafting the initial protocol-level handshake could, with valid credentials for any account, specify a target account and switch into it immediately. This includes any other tenant, and includes the System account which controls nats-server core operations.
For deployments not using multi-tenancy through NATS Accounts, there is still a vulnerability: normal users are able to choose to be in the System account.
An experimental feature to provide dynamically provisioned sandbox accounts was designed to allow a server administrator to turn on an option to allow clients to dynamically request a brand new account inline at connection time. This feature went nowhere, but lived on in the code and was used by a number of tests; support was never added to any client libraries or to the documentation.
A bug in handling the feature meant that if someone did in fact have valid account credentials, then they could specify any other existing account and they would be assigned into that account.
Release 2.7.2 of nats-server removes the feature. Because of the lack of client support and absence from protocol documentation, we feel this is safe operationally as well as the safest fix for the code.
Affected versions
NATS Server
- All 2.x versions up to and including 2.7.1.
- Fixed with nats-io/nats-server: 2.7.2
- NATS Server 1.x did not have accounts.
- Docker image: nats https://hub.docker.com/_/nats
NATS Streaming Server
- All versions embedding affected NATS Server:
- Affected: v0.15.0 up to and including v0.24.0
- Fixed with nats-io/nats-streaming-server: 0.24.1
- Docker image: nats-streaming https://hub.docker.com/_/nats-streaming
Impact
Existing users could act in any account, including the System account.
Workaround
None.
Solution
Upgrade the NATS server.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/nats-io/nats-server | all versions |
No fix yet |
| github.com/nats-io/nats-server/v2 | >= 2.0.0, < 2.7.2 |
2.7.2 |
| github.com/nats-io/nats-streaming-server | >= 0.15.0, < 0.24.1 |
0.24.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/nats-io/nats-server/v2 Go → 2.7.2
- go
go get github.com/nats-io/nats-server/v2@v2.7.2 && go mod tidy
github.com/nats-io/nats-streaming-server Go → 0.24.1
- go
go get github.com/nats-io/nats-streaming-server@v0.24.1 && go mod tidy
Severity breakdown
CVSS 3.1 8.8
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-863: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-pq2q-rcw4-3hr6 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead | High | Also affects github.com/nats-io/nats-server |
| GHSA-3f24-pcvm-5jqc NATS has mTLS verify_and_map authentication bypass via incorrect Subject DN matching | Medium | Also affects github.com/nats-io/nats-server |
| GHSA-55h8-8g96-x4hj NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers | Medium | Also affects github.com/nats-io/nats-server |
| GHSA-pwx7-fx9r-hr4h NATS Server: Incomplete Stripping of Nats-Request-Info Header Allows Identity Spoofing | Medium | Also affects github.com/nats-io/nats-server |
| GHSA-9983-vrx2-fg9c NATS JetStream has an authorization bypass through its Management API | Medium | Also affects github.com/nats-io/nats-server |
| GHSA-8r68-gvr4-jh7j NATS is vulnerable to pre-auth DoS through WebSockets client service | Medium | Also affects github.com/nats-io/nats-server |
| GHSA-vprv-35vv-q339 NATS has pre-auth server panic via leafnode handling | High | Also affects github.com/nats-io/nats-server |
| GHSA-jxxm-27vp-c3m5 NATS allows MQTT clients to bypass ACL checks | Medium | Also affects github.com/nats-io/nats-server |
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