unauthenticated proxy blocks

[akshaydeo]

Summary

Setting the outbound proxy URL is at least as sensitive as setting a provider's base URL: once enabled, the proxy replaces the HTTP client's Dial function entirely, routing every outbound provider request — including Authorization and x-api-key headers — through the attacker-chosen host. Without this fix, an unauthenticated caller on the network could set the proxy URL while dashboard auth is disabled or unconfigured, since the auth middleware's fail-open branch previously granted the same IsLocalAdminContextKey flag as a genuinely authenticated session.

Changes

• Introduced BifrostContextKeyAuthBypassed context key, set exclusively in the auth middleware's fail-open branch (when authConfig == nil or auth is disabled), distinct from IsLocalAdminContextKey which is also true for real authenticated sessions.
• Added isAuthBypassed helper in the config handler to read this key.
• Gated the "enable proxy with URL" path in updateProxyConfig behind isAuthBypassed: returns 403 Forbidden if the request was not genuinely authenticated, while the rest of the management API remains accessible under the default-open posture.
• The pre-existing empty-URL 400 validation intentionally runs before the auth gate so a malformed request does not leak whether dashboard auth is configured.
• Added OpenAPI documentation for the new 403 response on PUT /proxy-config, including an updated endpoint description explaining the restriction.
• Added config_proxy_ssrf_test.go with two tests: one proving an auth-bypassed caller cannot set the proxy URL, and one proving the empty-URL 400 still fires first for an invalid request.

Type of change

• Bug fix
• Feature
• Refactor
• Documentation
• Chore/CI

Affected areas

• Core (Go)
• Transports (HTTP)
• Providers/Integrations
• Plugins
• UI (React)
• Docs

How to test

go test ./transports/bifrost-http/handlers/... -run TestUpdateProxyConfig

Expected outcomes:

• TestUpdateProxyConfig_UnauthenticatedWriteRejected — PUT /proxy-config with enabled: true and a URL while BifrostContextKeyAuthBypassed is set returns 403.
• TestUpdateProxyConfig_EmptyURLCheckRunsBeforeAuthGate — PUT /proxy-config with enabled: true and an empty URL while BifrostContextKeyAuthBypassed is set returns 400, not 403.

To verify end-to-end: disable dashboard authentication, then attempt to PUT /proxy-config with a valid proxy URL. The request should be rejected with 403. Disabling the proxy (setting enabled: false) should remain unrestricted.

Breaking changes

• Yes
• No

Security considerations

This closes an SSRF-adjacent privilege escalation: without dashboard authentication configured, any network-reachable caller could previously redirect all outbound provider traffic — including API keys — through an arbitrary host. The fix ensures that enabling the outbound proxy always requires a genuinely authenticated admin session, independent of the global fail-open posture applied to the rest of the management API.

Checklist

• I read docs/contributing/README.md and followed the guidelines
• I added/updated tests where appropriate
• I updated documentation where needed
• I verified builds succeed (Go and UI)
• I verified the CI pipeline passes locally if applicable

[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes

  • Proxy URL updates now require authenticated admin access when dashboard authentication is disabled or bypassed.
  • Added protection against unauthenticated requests configuring attacker-controlled proxy endpoints.
  • Empty proxy URLs are rejected with a clear validation error.

• Documentation

  • Updated API documentation to describe authentication requirements and possible forbidden responses for proxy configuration updates.

Walkthrough

The authentication middleware now marks bypassed requests. Proxy configuration rejects enabled proxy URLs from those requests with HTTP 403. Tests cover rejection and validation precedence. OpenAPI documentation describes the authentication requirement and response.

Changes

Proxy configuration authentication

Layer / File(s)	Summary
Authentication bypass context core/schemas/bifrost.go, transports/bifrost-http/handlers/middlewares.go	Adds BifrostContextKeyAuthBypassed and records it when authentication is disabled or unconfigured.
Proxy URL enforcement and validation transports/bifrost-http/handlers/config.go, transports/bifrost-http/handlers/config_proxy_ssrf_test.go	Rejects enabled proxy URL updates from bypassed requests with HTTP 403. Tests preserve empty-URL validation with HTTP 400.
OpenAPI contract docs/openapi/paths/management/config.yaml	Documents the authenticated access requirement and the HTTP 403 response.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Client
  participant AuthMiddleware
  participant updateProxyConfig
  participant HTTPResponse
  Client->>AuthMiddleware: Send proxy configuration request
  AuthMiddleware->>updateProxyConfig: Pass request with bypass context
  updateProxyConfig->>HTTPResponse: Return 403 for enabled proxy URL

Loading

Possibly related PRs

• maximhq/bifrost#5760: Uses the same bypass marker to protect sensitive admin operations.
• maximhq/bifrost#5763: Applies the same bypass marker to plugin management.
• maximhq/bifrost#5768: Adds authentication safeguards for endpoint URL changes.

Suggested reviewers: madhuvod, pratham-mishra04, tejasghatte

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	The changes address proxy authentication, not the linked issue's requested Files API support for providers.	Implement the requested Files API support, or link the PR to an issue that covers the proxy authentication fix.
Out of Scope Changes check	⚠️ Warning	The proxy authentication and SSRF protections are unrelated to the linked issue's Files API objectives.	Update the linked issue to match this security fix, or remove the unrelated Files API issue link.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title clearly identifies the main change: blocking unauthenticated proxy configuration.
Description check	✅ Passed	The description explains the security issue, implementation, tests, affected areas, documentation, and security considerations.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch block-unauthenticated-proxy-config-writes

---

_{Comment @coderabbitai help to get the list of available commands.}

[akshaydeo]

• unauthenticated proxy blocks #5778 👈 (View in Graphite)
• dev

This stack of pull requests is managed by Graphite. Learn more about stacking.

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@transports/bifrost-http/handlers/config_proxy_ssrf_test.go`:
- Line 1: Rename the test file from config_proxy_ssrf_test.go to
configproxyssrf_test.go, preserving its package and contents while removing
underscores before the required _test.go suffix.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: e2dea860-38e2-4c09-9f9c-a08aa7beef0f

📥 Commits

Reviewing files that changed from the base of the PR and between cc45872 and c5668ae.

📒 Files selected for processing (5)

• core/schemas/bifrost.go
• docs/openapi/paths/management/config.yaml
• transports/bifrost-http/handlers/config.go
• transports/bifrost-http/handlers/config_proxy_ssrf_test.go
• transports/bifrost-http/handlers/middlewares.go

[coderabbitai]

📐 Maintainability & Code Quality | 🟡 Minor | ⚡ Quick win

Rename the test file to meet the Go filename rule.

config_proxy_ssrf_test.go contains underscores before its required _test.go suffix. Rename it to configproxyssrf_test.go.

As per coding guidelines, “Go filenames must contain no underscores except the _test.go suffix.” Based on learnings, the underscore exception applies only to non-test Go files.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@transports/bifrost-http/handlers/config_proxy_ssrf_test.go` at line 1, Rename
the test file from config_proxy_ssrf_test.go to configproxyssrf_test.go,
preserving its package and contents while removing underscores before the
required _test.go suffix.

Sources: Coding guidelines, Learnings