Ubuntu 17.04 / 17.10 : exim4 vulnerability (USN-3493-1)

2017-11-28T00:00:00
ID UBUNTU_USN-3493-1.NASL
Type nessus
Reporter Ubuntu Security Notice (C) 2017-2019 Canonical, Inc. / NASL script (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-05-02T00:00:00

Description

It was discovered that Exim incorrectly handled memory in the ESMTP CHUNKING extension. A remote attacker could use this issue to cause Exim to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3493-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(104808);
  script_version("3.5");
  script_cvs_date("Date: 2019/09/18 12:31:47");

  script_cve_id("CVE-2017-16943");
  script_xref(name:"USN", value:"3493-1");

  script_name(english:"Ubuntu 17.04 / 17.10 : exim4 vulnerability (USN-3493-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that Exim incorrectly handled memory in the ESMTP
CHUNKING extension. A remote attacker could use this issue to cause
Exim to crash, resulting in a denial of service, or possibly execute
arbitrary code. The default compiler options for affected releases
should reduce the vulnerability to a denial of service.

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://usn.ubuntu.com/3493-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected exim4-daemon-heavy and / or exim4-daemon-light
packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:exim4-daemon-heavy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:exim4-daemon-light");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:17.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:17.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/11/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/11/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/11/28");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2017-2019 Canonical, Inc. / NASL script (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(17\.04|17\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 17.04 / 17.10", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

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

flag = 0;

if (ubuntu_check(osver:"17.04", pkgname:"exim4-daemon-heavy", pkgver:"4.88-5ubuntu1.2")) flag++;
if (ubuntu_check(osver:"17.04", pkgname:"exim4-daemon-light", pkgver:"4.88-5ubuntu1.2")) flag++;
if (ubuntu_check(osver:"17.10", pkgname:"exim4-daemon-heavy", pkgver:"4.89-5ubuntu1.1")) flag++;
if (ubuntu_check(osver:"17.10", pkgname:"exim4-daemon-light", pkgver:"4.89-5ubuntu1.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "exim4-daemon-heavy / exim4-daemon-light");
}