Arcane: Environment access token bypasses the admin-required authorization gate on `/api/debug/pprof`

Summary

Arcane v2.10.2 contains an authorization inconsistency in AuthMiddleware.managerAuth.

When a request supplies a valid environment access token through the X-Arcane-Agent-Token header, managerAuth resolves the associated environment, installs an environment-scoped permission set, and immediately calls next(c).

This occurs before the middleware evaluates the AdminRequired option and verifies that the caller is a global administrator.

As a result, an environment-scoped access token can access routes protected with WithAdminRequired(), despite the corresponding EnvironmentPermissionSet intentionally containing no global or sudo permissions.

In v2.10.2, the affected admin-only surface is the manager's Go pprof diagnostic interface under:

/api/debug/pprof/*

This exposes diagnostic and runtime profiling information that the application explicitly intends to restrict to global administrators.

The issue is an incorrect authorization vulnerability (CWE-863).

Details

1. Environment access tokens are accepted by the manager authentication middleware

The production authentication middleware is configured with an environment access-token resolver:

backend/internal/di/providers.go

Conceptually, the middleware is constructed as:

auth.NewAuthMiddleware(authService, cfg).
    WithApiKeyValidator(apiKey).
    WithEnvironmentAccessTokenResolver(env).
    WithPermissionResolver(role)

Therefore, the X-Arcane-Agent-Token authentication path is active in the production manager.

2. The environment-token path returns before authorization options are evaluated

The relevant logic is in:

backend/internal/auth/middleware.go

managerAuth first checks the X-Arcane-Agent-Token header.

When the token resolves to an environment, the middleware installs an environment-scoped permission set and immediately continues processing:

if agentToken := req.Header.Get(utils.HeaderAgentToken); agentToken != "" {
    if env, ok := m.resolveEnvironmentAccessToken(ctx, agentToken).Get(); ok {
        environmentScopedInternal(c, env)
        return next(c)
    }
}

The important part is the unconditional:

return next(c)

The normal authentication path later evaluates the middleware's AdminRequired option:

ps := m.resolvePermissionsOrDeny(ctx, user)

if m.options.AdminRequired && !ps.IsGlobalAdmin() {
    return c.JSON(http.StatusForbidden, common.APIError{
        Code:    "FORBIDDEN",
        Message: "You don't have permission to access this resource",
    })
}

The environment-token branch never reaches this check.

Consequently, WithAdminRequired() has no effect when authentication succeeds through a valid environment access token.

This creates an authorization inconsistency between authentication mechanisms:

• normal user/session authentication → AdminRequired is enforced;

• environment access-token authentication → AdminRequired is bypassed.

3. Environment tokens are intentionally not global-administrator credentials

backend/pkg/authz/permission_set.go defines the effective permissions assigned to an environment access token.

EnvironmentPermissionSet(envID) grants environment-scoped permissions only for the specified environment:

func EnvironmentPermissionSet(envID string) *PermissionSet {
    ps := NewPermissionSet()

    if envID == "" {
        return ps
    }

    for _, p := range AllPermissions() {
        if IsEnvScoped(p) {
            ps.AddEnv(envID, p)
        }
    }

    return ps
}

The implementation explicitly establishes that these credentials do not receive global or sudo permissions.

Therefore, an environment access token should not satisfy a global-administrator authorization requirement.

The early return in managerAuth bypasses this intended privilege boundary.

4. /api/debug/pprof/* explicitly requires global-administrator authorization

The diagnostic routes are registered in:

backend/api/ws/diagnostics.go

The pprof group is protected using:

pprofGroup := group.Group(
    "/debug/pprof",
    authMiddleware.WithAdminRequired().Add(),
)

The source also documents the intended authorization requirement by noting that pprof keeps the stricter admin-required gate.

The group exposes handlers including:

/api/debug/pprof/
/api/debug/pprof/cmdline
/api/debug/pprof/profile
/api/debug/pprof/symbol
/api/debug/pprof/trace
/api/debug/pprof/heap
/api/debug/pprof/goroutine
/api/debug/pprof/allocs
/api/debug/pprof/block
/api/debug/pprof/mutex
/api/debug/pprof/threadcreate

Named profiles are dispatched through pprof.Handler.

Because WithAdminRequired() is bypassed by the environment-token branch, a valid environment access token can reach these handlers even though its permission set is not globally privileged.

5. Other middleware does not restore the missing authorization check

The CSRF middleware recognizes X-Arcane-Agent-Token as a header-based credential and does not apply the normal cross-origin CSRF validation to such requests.

Additionally, the environment proxy middleware passes through requests that do not target an /environments/{id}/... path.

Therefore a request to:

/api/debug/pprof/*

can proceed to managerAuth, enter the environment-token authentication branch, and reach the pprof handler without another global-administrator authorization check being applied.

Source-to-sink authorization path

The vulnerable control flow is:

X-Arcane-Agent-Token
        |
        v
environment access token resolver
        |
        v
environment resolved successfully
        |
        v
EnvironmentPermissionSet(environmentID)
        |
        v
return next(c)
        |
        |  AdminRequired check is skipped
        v
/api/debug/pprof/*
        |
        v
net/http/pprof handler

The security boundary violation occurs at the early return next(c).

Proof of Concept

Preconditions

The test requires:

1. A valid Arcane environment access token.

2. An Arcane manager running the affected code.

3. No global-administrator account or credentials.

Test 1 — environment access token

Send a request to an admin-protected pprof endpoint using only an environment access token:

GET /api/debug/pprof/heap?debug=1 HTTP/1.1
Host: arcane.example.com
X-Arcane-Agent-Token: <VALID_ENVIRONMENT_ACCESS_TOKEN>

No administrator session cookie or administrator Bearer token is supplied.

Vulnerable behavior

On an affected instance, the request is expected to reach the pprof handler instead of being rejected by WithAdminRequired().

A successful response demonstrates that the environment-token authentication branch bypasses the administrator requirement.

For example, the response may contain the Go heap profiling output generated by net/http/pprof.

Test 2 — non-admin user contrast case

Send the same request using a normal authenticated non-global-admin user:

GET /api/debug/pprof/heap?debug=1 HTTP/1.1
Host: arcane.example.com
Authorization: Bearer <NON_ADMIN_ACCESS_TOKEN>

The expected result is:

HTTP/1.1 403 Forbidden

with an authorization error indicating that the user does not have permission to access the resource.

This contrast demonstrates the authorization inconsistency:

environment-scoped token
        -> admin gate skipped
        -> pprof handler reached

normal non-admin user
        -> admin gate evaluated
        -> HTTP 403

Expected secure behavior

A valid environment access token should receive:

HTTP/1.1 403 Forbidden

for every route protected with WithAdminRequired().

Only a caller whose effective permission set satisfies IsGlobalAdmin() should be allowed to access these routes.

Impact

An attacker who obtains a valid environment access token can cross the intended authorization boundary between an individual environment and manager-w