Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Dovecot vulnerabilities (USN-4456-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4456-1. 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(139567);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2020-12100", "CVE-2020-12673", "CVE-2020-12674");
  script_xref(name:"USN", value:"4456-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Dovecot vulnerabilities (USN-4456-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"It was discovered that Dovecot incorrectly handled deeply nested MIME
parts. A remote attacker could possibly use this issue to cause
Dovecot to consume resources, resulting in a denial of service.
(CVE-2020-12100) It was discovered that Dovecot incorrectly handled
memory when using NTLM. A remote attacker could possibly use this
issue to cause Dovecot to crash, resulting in a denial of service.
(CVE-2020-12673) It was discovered that the Dovecot RPA mechanism
incorrectly handled zero-length messages. A remote attacker could
possibly use this issue to cause Dovecot to crash, resulting in a
denial of service. (CVE-2020-12674).

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://ubuntu.com/security/notices/USN-4456-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-12674");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/08/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/08/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/08/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-gssapi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-imapd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-lmtpd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-lucene");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-managesieved");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-pop3d");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-sieve");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-solr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-sqlite");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-submissiond");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mail-stack-delivery");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot-auth-lua");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2020-2023 Canonical, Inc. / NASL script (C) 2020-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '16.04', 'pkgname': 'dovecot-core', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-dev', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-gssapi', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-imapd', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-ldap', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-lmtpd', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-lucene', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-managesieved', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-mysql', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-pgsql', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-pop3d', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-sieve', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-solr', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'dovecot-sqlite', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'mail-stack-delivery', 'pkgver': '1:2.2.22-1ubuntu2.13'},
    {'osver': '18.04', 'pkgname': 'dovecot-core', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-dev', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-gssapi', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-imapd', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-ldap', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-lmtpd', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-managesieved', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-mysql', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-pgsql', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-pop3d', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-sieve', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-solr', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'dovecot-sqlite', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '18.04', 'pkgname': 'mail-stack-delivery', 'pkgver': '1:2.2.33.2-1ubuntu4.6'},
    {'osver': '20.04', 'pkgname': 'dovecot-auth-lua', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-core', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-dev', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-gssapi', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-imapd', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-ldap', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-lmtpd', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-lucene', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-managesieved', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-mysql', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-pgsql', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-pop3d', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-sieve', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-solr', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-sqlite', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'dovecot-submissiond', 'pkgver': '1:2.3.7.2-1ubuntu3.2'},
    {'osver': '20.04', 'pkgname': 'mail-stack-delivery', 'pkgver': '1:2.3.7.2-1ubuntu3.2'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'dovecot-auth-lua / dovecot-core / dovecot-dev / dovecot-gssapi / etc');
}