OpenShift bare metal provisioning: unauthenticated image server leaks cluster pull secret

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

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

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

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.