CVE-2026-96628: Arcane Environment Access Token Bypasses The Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mp22-58ff-6fhr",
  "modified" : "2026-10-16T21:12:04Z",
  "published" : "2026-10-16T21:12:03Z",
  "aliases" : [ "CVE-2026-96628" ],
  "summary" : "Arcane: Environment access token bypasses the admin-required authorization gate on `/api/debug/pprof`",
  "details" : "## Summary\n\nArcane v2.10.2 contains an authorization inconsistency in `AuthMiddleware.managerAuth`.\n\nWhen 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)`.\n\nThis occurs before the middleware evaluates the `AdminRequired` option and verifies that the caller is a global administrator.\n\nAs a result, an environment-scoped access token can access routes protected with `WithAdminRequired()`, despite the corresponding `EnvironmentPermissionSet` intentionally containing no global or sudo permissions.\n\nIn v2.10.2, the affected admin-only surface is the manager's Go `pprof` diagnostic interface under:\n\n`/api/debug/pprof/*`\n\nThis exposes diagnostic and runtime profiling information that the application explicitly intends to restrict to global administrators.\n\nThe issue is an incorrect authorization vulnerability (CWE-863).\n\n## Details\n\n### 1. Environment access tokens are accepted by the manager authentication middleware\n\nThe production authentication middleware is configured with an environment access-token resolver:\n\n`backend/internal/di/providers.go`\n\nConceptually, the middleware is constructed as:\n\n```go\nauth.NewAuthMiddleware(authService, cfg).\n    WithApiKeyValidator(apiKey).\n    WithEnvironmentAccessTokenResolver(env).\n    WithPermissionResolver(role)\n```\n\nTherefore, the `X-Arcane-Agent-Token` authentication path is active in the production manager.\n\n### 2. The environment-token path returns before authorization options are evaluated\n\nThe relevant logic is in:\n\n`backend/internal/auth/middleware.go`\n\n`managerAuth` first checks the `X-Arcane-Agent-Token` header.\n\nWhen the token resolves to an environment, the middleware installs an environment-scoped permission set and immediately continues processing:\n\n```go\nif agentToken := req.Header.Get(utils.HeaderAgentToken); agentToken != \"\" {\n    if env, ok := m.resolveEnvironmentAccessToken(ctx, agentToken).Get(); ok {\n        environmentScopedInternal(c, env)\n        return next(c)\n    }\n}\n```\n\nThe important part is the unconditional:\n\n```go\nreturn next(c)\n```\n\nThe normal authentication path later evaluates the middleware's `AdminRequired` option:\n\n```go\nps := m.resolvePermissionsOrDeny(ctx, user)\n\nif m.options.AdminRequired && !ps.IsGlobalAdmin() {\n    return c.JSON(http.StatusForbidden, common.APIError{\n        Code:    \"FORBIDDEN\",\n        Message: \"You don't have permission to access this resource\",\n    })\n}\n```\n\nThe environment-token branch never reaches this check.\n\nConsequently, `WithAdminRequired()` has no effect when authentication succeeds through a valid environment access token.\n\nThis creates an authorization inconsistency between authentication mechanisms:\n\n- normal user/session authentication → `AdminRequired` is enforced;\n    \n- environment access-token authentication → `AdminRequired` is bypassed.\n    \n\n### 3. Environment tokens are intentionally not global-administrator credentials\n\n`backend/pkg/authz/permission_set.go` defines the effective permissions assigned to an environment access token.\n\n`EnvironmentPermissionSet(envID)` grants environment-scoped permissions only for the specified environment:\n\n```go\nfunc EnvironmentPermissionSet(envID string) *PermissionSet {\n    ps := NewPermissionSet()\n\n    if envID == \"\" {\n        return ps\n    }\n\n    for _, p := range AllPermissions() {\n        if IsEnvScoped(p) {\n            ps.AddEnv(envID, p)\n        }\n    }\n\n    return ps\n}\n```\n\nThe implementation explicitly establishes that these credentials do not receive global or sudo permissions.\n\nTherefore, an environment access token should not satisfy a global-administrator authorization requirement.\n\nThe early return in `managerAuth` bypasses this intended privilege boundary.\n\n### 4. `/api/debug/pprof/*` explicitly requires global-administrator authorization\n\nThe diagnostic routes are registered in:\n\n`backend/api/ws/diagnostics.go`\n\nThe `pprof` group is protected using:\n\n```go\npprofGroup := group.Group(\n    \"/debug/pprof\",\n    authMiddleware.WithAdminRequired().Add(),\n)\n```\n\nThe source also documents the intended authorization requirement by noting that pprof keeps the stricter admin-required gate.\n\nThe group exposes handlers including:\n\n```text\n/api/debug/pprof/\n/api/debug/pprof/cmdline\n/api/debug/pprof/profile\n/api/debug/pprof/symbol\n/api/debug/pprof/trace\n/api/debug/pprof/heap\n/api/debug/pprof/goroutine\n/api/debug/pprof/allocs\n/api/debug/pprof/block\n/api/debug/pprof/mutex\n/api/debug/pprof/threadcreate\n```\n\nNamed profiles are dispatched through `pprof.Handler`.\n\nBecause `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.\n\n### 5. Other middleware does not restore the missing authorization check\n\nThe 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.\n\nAdditionally, the environment proxy middleware passes through requests that do not target an `/environments/{id}/...` path.\n\nTherefore a request to:\n\n```text\n/api/debug/pprof/*\n```\n\ncan proceed to `managerAuth`, enter the environment-token authentication branch, and reach the pprof handler without another global-administrator authorization check being applied.\n\n## Source-to-sink authorization path\n\nThe vulnerable control flow is:\n\n```text\nX-Arcane-Agent-Token\n        |\n        v\nenvironment access token resolver\n        |\n        v\nenvironment resolved successfully\n        |\n        v\nEnvironmentPermissionSet(environmentID)\n        |\n        v\nreturn next(c)\n        |\n        |  AdminRequired check is skipped\n        v\n/api/debug/pprof/*\n        |\n        v\nnet/http/pprof handler\n```\n\nThe security boundary violation occurs at the early `return next(c)`.\n\n## Proof of Concept\n\n### Preconditions\n\nThe test requires:\n\n1. A valid Arcane environment access token.\n    \n2. An Arcane manager running the affected code.\n    \n3. No global-administrator account or credentials.\n    \n\n### Test 1 — environment access token\n\nSend a request to an admin-protected pprof endpoint using only an environment access token:\n\n```http\nGET /api/debug/pprof/heap?debug=1 HTTP/1.1\nHost: arcane.example.com\nX-Arcane-Agent-Token: <VALID_ENVIRONMENT_ACCESS_TOKEN>\n```\n\nNo administrator session cookie or administrator Bearer token is supplied.\n\n### Vulnerable behavior\n\nOn an affected instance, the request is expected to reach the pprof handler instead of being rejected by `WithAdminRequired()`.\n\nA successful response demonstrates that the environment-token authentication branch bypasses the administrator requirement.\n\nFor example, the response may contain the Go heap profiling output generated by `net/http/pprof`.\n\n### Test 2 — non-admin user contrast case\n\nSend the same request using a normal authenticated non-global-admin user:\n\n```http\nGET /api/debug/pprof/heap?debug=1 HTTP/1.1\nHost: arcane.example.com\nAuthorization: Bearer <NON_ADMIN_ACCESS_TOKEN>\n```\n\nThe expected result is:\n\n```http\nHTTP/1.1 403 Forbidden\n```\n\nwith an authorization error indicating that the user does not have permission to access the resource.\n\nThis contrast demonstrates the authorization inconsistency:\n\n```text\nenvironment-scoped token\n        -> admin gate skipped\n        -> pprof handler reached\n\nnormal non-admin user\n        -> admin gate evaluated\n        -> HTTP 403\n```\n\n### Expected secure behavior\n\nA valid environment access token should receive:\n\n```http\nHTTP/1.1 403 Forbidden\n```\n\nfor every route protected with `WithAdminRequired()`.\n\nOnly a caller whose effective permission set satisfies `IsGlobalAdmin()` should be allowed to access these routes.\n\n## Impact\n\nAn attacker who obtains a valid environment access token can cross the intended authorization boundary between an individual environment and manager-wide administrative functionality.\n\nIn the currently identified route configuration, this allows unauthorized access to the manager's Go `pprof` diagnostic endpoints.\n\nDepending on the requested profile, these endpoints can expose internal runtime and diagnostic information such as:\n\n- goroutine stack traces;\n    \n- function and package names;\n    \n- allocation and heap profiling information;\n    \n- CPU profiling information;\n    \n- runtime execution traces;\n    \n- process command-line information;\n    \n- mutex, block, thread and allocation profiling data.\n    \n\nThis information is normally restricted to global administrators by Arcane's explicit use of `WithAdminRequired()`.\n\nSome profiling operations may also impose additional CPU, memory, or tracing overhead while being collected.\n\nImportantly, this report does **not** assume that Go's pprof heap endpoint is an arbitrary raw-process-memory dump. Direct extraction of session tokens, environment access tokens, passwords, or other credentials from pprof output has not been demonstrated and is therefore not claimed as part of the confirmed impact.\n\nThe confirmed security issue is the authorization bypass itself and the resulting unauthorized exposure of administrator-restricted diagnostic functionality.\n\n## Root Cause\n\nThe root cause is that authentication through an environment access token takes an early-success path:\n\n```go\nenvironmentScopedInternal(c, env)\nreturn next(c)\n```\n\nbefore common middleware authorization options are evaluated.\n\nAs a result, authorization requirements configured on the middleware are dependent on which authentication mechanism is used.\n\nAuthentication establishes the identity and scope of the caller, but route-level authorization requirements such as `AdminRequired` should subsequently be applied consistently regardless of the authentication mechanism.\n\n## Remediation\n\nThe environment-token authentication path should not call `next(c)` before the configured authorization requirements have been evaluated.\n\nOne approach is to resolve the environment token into its `EnvironmentPermissionSet` and then pass that permission set through the same authorization-option evaluation used by other authentication mechanisms.\n\nFor example, logically:\n\n```go\nif envTokenIsValid {\n    ps := authz.EnvironmentPermissionSet(env.ID)\n\n    if m.options.AdminRequired && !ps.IsGlobalAdmin() {\n        return forbidden\n    }\n\n    environmentScopedInternal(c, env)\n    return next(c)\n}\n```\n\nBecause an `EnvironmentPermissionSet` intentionally has no global permissions, an environment token would then correctly receive HTTP 403 for `WithAdminRequired()` routes.\n\nAs additional defense in depth, the pprof endpoints could explicitly reject environment access tokens and other environment-scoped authentication mechanisms, allowing access only through authentication mechanisms capable of representing a global administrator.\n\nIt may also be worth considering whether pprof should be exposed in production by default or enabled only through an explicit diagnostic configuration option.\n\n## Regression Tests\n\nThe following cases should be covered:\n\n```text\nValid environment access token\n+ /api/debug/pprof/heap\n=> 403\n\nNormal authenticated non-admin user\n+ /api/debug/pprof/hea\n=> 403\n\nUnauthenticated request\n+ /api/debug/pprof/heap\n=> 401/403\n\nGlobal administrator\n+ /api/debug/pprof/heap\n=> 200\n```\n\nMore generally, tests should verify that every authentication mechanism is subject to middleware options such as `AdminRequired`.\n\nThe issue could also broadly be categorized as an authorization-check bypass caused by inconsistent authorization handling across authentication paths..\n \n\nNo claim of credential extraction, arbitrary process-memory disclosure, or global-administrator takeover is made unless separately demonstrated through dynamic testing.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/getarcaneapp/arcane/backend/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.11.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/getarcaneapp/arcane/security/advisories/GHSA-mp22-58ff-6fhr"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getarcaneapp/arcane/pull/3881"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getarcaneapp/arcane/commit/4fe4c7ed9483dff7d43e3c4bee6a92037ce886b4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/getarcaneapp/arcane"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getarcaneapp/arcane/releases/tag/backend/v2.11.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-16T21:12:03Z",
    "nvd_published_at" : null
  }
}