CVE-2026-82976 Image-customization-controller: unauthenticated plaintext image server with directory listing exposes ignition images containing cluster pull secret

Description

A flaw was found in the image-customization-controller used in OpenShift's bare metal provisioning stack. The controller registers an HTTP file server on port 8084 with no authentication. The custom imageFileSystem implementation exposes a browsable HTML directory listing of all registered images at the root path. The only access control on per-host images is the random UUID filename; the directory listing discloses those UUIDs to any caller on the provisioning network. Each served image embeds an Ignition config containing the base64-encoded cluster pull secret, optional IRONIC_RAMDISK_SSH_KEY, proxy settings, and per-host NetworkManager keyfiles. An adjacent network attacker can enumerate all image UUIDs via directory listing, download any image, extract the embedded Ignition config, and recover the cluster pull secret and SSH key. ### Evidence **pkg/imagehandler/imagefilesystem.go — root directory is browsable and enumerates all UUID image names** ```go func (f *imageFileSystem) Readdir(n int) ([]fs.FileInfo, error) { f.mu.Lock() defer f.mu.Unlock() result := []fs.FileInfo{} for _, im := range f.images { result = append(result, im) } return result, nil } func (f *imageFileSystem) Open(name string) (http.File, error) { f.log.Info("Open", "path", name) if name == "/" { return f, nil } ... ``` **cmd/controller/main.go — file server bound on all interfaces without auth or TLS** ```go http.Handle("/", http.FileServer(imageServer.FileSystem())) go func() { server := &http.Server{ Addr: imagesBindAddr, // default ":8084" ReadHeaderTimeout: 5 * time.Second, } err := server.ListenAndServe() ``` **pkg/ignition/service_config.go:94-100 — pull secret is embedded in every served image** ```go func (b *ignitionBuilder) authFile() ignition_config_types_32.File { source := "data:;base64," + strings.TrimSpace(b.ironicAgentPullSecret) return ignition_config_types_32.File{ Node: ignition_config_types_32.Node{Path: "/etc/authfile.json"}, ... ``` ### Attack Pattern Adjacent provisioning-network client → GET / lists UUID image names → download ISO/initramfs → extract embedded Ignition → recover cluster pull secret and SSH key.

Exploitable depuis le réseau local, sans compte et sans action d’un utilisateur ; un attaquant peut compromettre gravement la confidentialité, l’intégrité ou la disponibilité.

Vecteur d’attaque

Réseau adjacent

Complexité

Faible

Privilèges requis

Aucun

Interaction

Aucune

Portée

Inchangée

Confidentialité

Élevé

Intégrité

Faible

Disponibilité

Aucun

Produits et versions touchés