CentOS 4 / 5 : exim (CESA-2011:0153) - Nessus

Medium Plugin ID: 51785

This page contains detailed information about the CentOS 4 / 5 : exim (CESA-2011:0153) 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: 51785
Name: CentOS 4 / 5 : exim (CESA-2011:0153)
Filename: centos_RHSA-2011-0153.nasl
Vulnerability Published: 2010-12-14
This Plugin Published: 2011-01-28
Last Modification Time: 2022-03-28
Plugin Version: 1.16
Plugin Type: local
Plugin Family: CentOS Local Security Checks
Dependencies: ssh_get_info.nasl
Required KB Items [?]: Host/CentOS/release, Host/CentOS/rpm-list, Host/local_checks_enabled

Vulnerability Information

Severity: Medium
Vulnerability Published: 2010-12-14
Patch Published: 2011-04-14
CVE [?]: CVE-2010-4345
CPE [?]: cpe:/o:centos:centos:4, cpe:/o:centos:centos:5, p-cpe:/a:centos:centos:exim, p-cpe:/a:centos:centos:exim-doc, p-cpe:/a:centos:centos:exim-mon, p-cpe:/a:centos:centos:exim-sa

Synopsis

The remote CentOS host is missing one or more security updates.

Description

Updated exim packages that fix one security issue are now available for Red Hat Enterprise Linux 4 and 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

Exim is a mail transport agent (MTA) developed at the University of Cambridge for use on UNIX systems connected to the Internet.

A privilege escalation flaw was discovered in Exim. If an attacker were able to gain access to the 'exim' user, they could cause Exim to execute arbitrary commands as the root user. (CVE-2010-4345)

This update adds a new configuration file, '/etc/exim/trusted-configs'. To prevent Exim from running arbitrary commands as root, Exim will now drop privileges when run with a configuration file not listed as trusted. This could break backwards compatibility with some Exim configurations, as the trusted-configs file only trusts '/etc/exim/exim.conf' and '/etc/exim/exim4.conf' by default. If you are using a configuration file not listed in the new trusted-configs file, you will need to add it manually.

Additionally, Exim will no longer allow a user to execute exim as root with the -D command line option to override macro definitions. All macro definitions that require root permissions must now reside in a trusted configuration file.

Users of Exim are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, the exim daemon will be restarted automatically.

Solution

Update the affected exim packages.

Public Exploits

Target Network Port(s): N/A
Target Asset(s): N/A
Exploit Available: True (Metasploit Framework, Exploit-DB)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the CentOS 4 / 5 : exim (CESA-2011:0153) vulnerability:

Metasploit: exploit/unix/smtp/exim4_string_format
[Exim4 string_format Function Heap Buffer Overflow]
Exploit-DB: exploits/linux/remote/16925.rb
[EDB-16925: Exim4 < 4.69 - string_format Function Heap Buffer Overflow (Metasploit)]

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 Score Source [?]: CVE-2010-4345
CVSS V2 Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C/E:H/RL:OF/RC:C

CVSS Base Score:	6.9 (Medium)
Impact Subscore:	10.0
Exploitability Subscore:	3.4
CVSS Temporal Score:	6.0 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.0 (Medium)

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Plugin Source

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2011:0153 and 
# CentOS Errata and Security Advisory 2011:0153 respectively.
#

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

if (description)
{
  script_id(51785);
  script_version("1.16");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/03/28");

  script_cve_id("CVE-2010-4345");
  script_bugtraq_id(45341);
  script_xref(name:"RHSA", value:"2011:0153");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/04/15");

  script_name(english:"CentOS 4 / 5 : exim (CESA-2011:0153)");

  script_set_attribute(attribute:"synopsis", value:
"The remote CentOS host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Updated exim packages that fix one security issue are now available
for Red Hat Enterprise Linux 4 and 5.

The Red Hat Security Response Team has rated this update as having
moderate security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from
the CVE link in the References section.

Exim is a mail transport agent (MTA) developed at the University of
Cambridge for use on UNIX systems connected to the Internet.

A privilege escalation flaw was discovered in Exim. If an attacker
were able to gain access to the 'exim' user, they could cause Exim to
execute arbitrary commands as the root user. (CVE-2010-4345)

This update adds a new configuration file,
'/etc/exim/trusted-configs'. To prevent Exim from running arbitrary
commands as root, Exim will now drop privileges when run with a
configuration file not listed as trusted. This could break backwards
compatibility with some Exim configurations, as the trusted-configs
file only trusts '/etc/exim/exim.conf' and '/etc/exim/exim4.conf' by
default. If you are using a configuration file not listed in the new
trusted-configs file, you will need to add it manually.

Additionally, Exim will no longer allow a user to execute exim as root
with the -D command line option to override macro definitions. All
macro definitions that require root permissions must now reside in a
trusted configuration file.

Users of Exim are advised to upgrade to these updated packages, which
contain a backported patch to correct this issue. After installing
this update, the exim daemon will be restarted automatically.");
  # https://lists.centos.org/pipermail/centos-announce/2011-April/017338.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1d0d8bfd");
  # https://lists.centos.org/pipermail/centos-announce/2011-April/017339.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?166cc0bc");
  # https://lists.centos.org/pipermail/centos-announce/2011-January/017243.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?87ec4edb");
  # https://lists.centos.org/pipermail/centos-announce/2011-January/017244.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?be520bee");
  script_set_attribute(attribute:"solution", value:
"Update the affected exim packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2010-4345");

  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:'Exim4 string_format Function Heap Buffer Overflow');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2010/12/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/04/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/01/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:exim");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:exim-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:exim-mon");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:exim-sa");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:5");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CentOS Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2011-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/CentOS/release");
if (isnull(release) || "CentOS" >!< release) audit(AUDIT_OS_NOT, "CentOS");
os_ver = pregmatch(pattern: "CentOS(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "CentOS");
os_ver = os_ver[1];
if (! preg(pattern:"^(4|5)([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 4.x / 5.x", "CentOS " + os_ver);

if (!get_kb_item("Host/CentOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && "ia64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "CentOS", cpu);


flag = 0;
if (rpm_check(release:"CentOS-4", cpu:"i386", reference:"exim-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"x86_64", reference:"exim-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"i386", reference:"exim-doc-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"x86_64", reference:"exim-doc-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"i386", reference:"exim-mon-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"x86_64", reference:"exim-mon-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"i386", reference:"exim-sa-4.43-1.RHEL4.5.el4_8.3")) flag++;
if (rpm_check(release:"CentOS-4", cpu:"x86_64", reference:"exim-sa-4.43-1.RHEL4.5.el4_8.3")) flag++;

if (rpm_check(release:"CentOS-5", reference:"exim-4.63-5.el5_6.2")) flag++;
if (rpm_check(release:"CentOS-5", reference:"exim-mon-4.63-5.el5_6.2")) flag++;
if (rpm_check(release:"CentOS-5", reference:"exim-sa-4.63-5.el5_6.2")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "exim / exim-doc / exim-mon / exim-sa");
}

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

Linux / Unix:
/opt/nessus/lib/nessus/plugins/centos_RHSA-2011-0153.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\centos_RHSA-2011-0153.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/centos_RHSA-2011-0153.nasl

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How to Run

Here is how to run the CentOS 4 / 5 : exim (CESA-2011:0153) 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 CentOS Local Security Checks plugin family.
On the right side table select CentOS 4 / 5 : exim (CESA-2011:0153) plugin ID 51785.
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 centos_RHSA-2011-0153.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a centos_RHSA-2011-0153.nasl -t <IP/HOST>

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

/opt/nessus/bin/nasl -T - centos_RHSA-2011-0153.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 centos_RHSA-2011-0153.nasl -t <IP/HOST>

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References

BID | SecurityFocus Bugtraq ID:

45341

RHSA | Red Hat Security Advisory:

2011:0153

See also:

Similar and related Nessus plugins:

51819 - Debian DSA-2154-1 : exim4 - privilege escalation
51446 - FreeBSD : exim -- local privilege escalation (e4fcf020-0447-11e0-becc-0022156e8794)
72159 - GLSA-201401-32 : Exim: Multiple vulnerabilities
68180 - Oracle Linux 4 / 5 : exim (ELSA-2011-0153)
51562 - RHEL 4 / 5 : exim (RHSA-2011:0153)
60936 - Scientific Linux Security Update : exim on SL4.x, SL5.x i386/x86_64
53657 - openSUSE Security Update : exim (openSUSE-SU-2010:1052-1)
53715 - openSUSE Security Update : exim (openSUSE-SU-2010:1052-1)
75481 - openSUSE Security Update : exim (openSUSE-SU-2010:1052-1)
51954 - Ubuntu 6.06 LTS / 8.04 LTS / 9.10 / 10.04 LTS / 10.10 : exim4 vulnerabilities (USN-1060-1)

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file centos_RHSA-2011-0153.nasl version 1.16. For more plugins, visit the Nessus Plugin Library.

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CentOS 4 / 5 : exim (CESA-2011:0153) - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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