Summary
Vanus 0.8.0 through 0.9.0 contains a missing authentication vulnerability in its CloudEvents HTTP gateway. An unauthenticated remote attacker may publish forged events to arbitrary event buses, causing them to be stored and delivered to subscription sinks when the gateway is exposed.
Vanus 0.8.0 through 0.9.0 contains a missing authentication vulnerability in its CloudEvents HTTP gateway. An unauthenticated remote attacker may publish forged events to arbitrary event buses, causing them to be stored and delivered to subscription sinks when the gateway is exposed.
Affected context
The issue occurs in Vanus deployments that expose the gateway CloudEvents HTTP receiver and rely on the affected event publication routes. Both the /namespaces/{ns}/eventbus/{name}/events path and the legacy /gateway/{name} path may accept event submissions without enforcing token authentication or publication authorization checks.
The issue occurs in Vanus deployments that expose the gateway CloudEvents HTTP receiver and rely on the affected event publication routes. Both the /namespaces/{ns}/eventbus/{name}/events path and the legacy /gateway/{name} path may accept event submissions without enforcing token authentication or publication authorization checks.
Exploit preconditions
- Attack surface: Network-accessible Vanus gateway HTTP endpoints
- Required access: No authentication or prior account access
- Trigger point: Submission of a CloudEvent to an eventbus publication route
- Why exploitation is possible: The gateway can process and publish events without enforcing token authentication and
authPublishauthorization checks
- Attack surface: Network-accessible Vanus gateway HTTP endpoints
- Required access: No authentication or prior account access
- Trigger point: Submission of a CloudEvent to an eventbus publication route
- Why exploitation is possible: The gateway can process and publish events without enforcing token authentication and
authPublishauthorization checks
Why this happens
The vulnerability results from an authentication and authorization control gap in the event publication gateway. Requests reaching affected CloudEvents receiver routes are processed without requiring a valid identity or verifying permission to publish to the selected eventbus. This maps to CWE-306: Missing Authentication for Critical Function, because a security-sensitive operation is available without an effective authentication requirement.
The vulnerability results from an authentication and authorization control gap in the event publication gateway. Requests reaching affected CloudEvents receiver routes are processed without requiring a valid identity or verifying permission to publish to the selected eventbus. This maps to CWE-306: Missing Authentication for Critical Function, because a security-sensitive operation is available without an effective authentication requirement.
Potential impact
- Attackers may inject forged or unauthorized events into event buses
- Subscription sinks may receive and process malicious or misleading data
- Downstream workflows could be triggered unexpectedly
- Event-driven applications may experience data integrity or availability issues
- Organizations could face unauthorized automation, notification, or business-process activity
- Attackers may inject forged or unauthorized events into event buses
- Subscription sinks may receive and process malicious or misleading data
- Downstream workflows could be triggered unexpectedly
- Event-driven applications may experience data integrity or availability issues
- Organizations could face unauthorized automation, notification, or business-process activity
General mitigation guidance
Mitigation generally focuses on enforcing authentication and authorization consistently across every event publication route, including legacy endpoints.
Common defensive patterns include:
- Require strong authentication before accepting event publication requests
- Enforce per-eventbus publish authorization after authentication
- Apply identical security middleware to current and legacy gateway paths
- Use deny-by-default access policies for externally reachable receivers
- Restrict gateway network exposure and place it behind authenticated ingress controls
- Validate event origin, tenant scope, and message integrity where appropriate
- Run downstream consumers with least privilege to limit the effect of forged events
Mitigation generally focuses on enforcing authentication and authorization consistently across every event publication route, including legacy endpoints.
Common defensive patterns include:
- Require strong authentication before accepting event publication requests
- Enforce per-eventbus publish authorization after authentication
- Apply identical security middleware to current and legacy gateway paths
- Use deny-by-default access policies for externally reachable receivers
- Restrict gateway network exposure and place it behind authenticated ingress controls
- Validate event origin, tenant scope, and message integrity where appropriate
- Run downstream consumers with least privilege to limit the effect of forged events
How teams detect issues like this
Organizations can identify this class of issue through:
- Static and architectural reviews confirming authentication middleware covers every event-ingestion route
- Code review checks for handlers that publish events before identity or permission validation
- Route inventories that include deprecated and legacy gateway paths
- API security tests that verify unauthenticated publication requests are rejected
- Gateway logs and metrics monitoring for event submissions lacking authenticated principals
- Policy enforcement requiring authentication and authorization tests for externally exposed event APIs
Automated API-security and code-review tools may help detect inconsistent control coverage, but deployment-level testing remains important.
Organizations can identify this class of issue through:
- Static and architectural reviews confirming authentication middleware covers every event-ingestion route
- Code review checks for handlers that publish events before identity or permission validation
- Route inventories that include deprecated and legacy gateway paths
- API security tests that verify unauthenticated publication requests are rejected
- Gateway logs and metrics monitoring for event submissions lacking authenticated principals
- Policy enforcement requiring authentication and authorization tests for externally exposed event APIs
Automated API-security and code-review tools may help detect inconsistent control coverage, but deployment-level testing remains important.
