Ubuntu 14.04 LTS : PAM regression (USN-2935-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2935-2. 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(89997);
  script_version("2.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");
  script_xref(name:"USN", value:"2935-2");

  script_name(english:"Ubuntu 14.04 LTS : PAM regression (USN-2935-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS host has packages installed that are affected by a vulnerability as referenced in the
USN-2935-2 advisory.

    USN-2935-1 fixed vulnerabilities in PAM. The updates contained a packaging change that prevented upgrades
    in certain multiarch environments. This update fixes the problem.

    We apologize for the inconvenience.

    Original advisory details:

    It was discovered that the PAM pam_userdb module incorrectly used a

    case-insensitive method when comparing hashed passwords. A local attacker

    could possibly use this issue to make brute force attacks easier. This

    issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7041)

    Sebastian Krahmer discovered that the PAM pam_timestamp module incorrectly

    performed filtering. A local attacker could use this issue to create

    arbitrary files, or possibly bypass authentication. This issue only

    affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-2583)

    Sebastien Macke discovered that the PAM pam_unix module incorrectly handled

    large passwords. A local attacker could possibly use this issue in certain

    environments to enumerate usernames or cause a denial of service.

    (CVE-2015-3238)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-2935-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_attribute(attribute:"risk_factor", value:"Medium");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2014/04/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/03/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/03/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-modules-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-runtime");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-cracklib");
  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) 2016-2024 Canonical, Inc. / NASL script (C) 2016-2024 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 (! ('14.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04', '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': '14.04', 'pkgname': 'libpam-cracklib', 'pkgver': '1.1.8-1ubuntu2.2'},
    {'osver': '14.04', 'pkgname': 'libpam-modules', 'pkgver': '1.1.8-1ubuntu2.2'},
    {'osver': '14.04', 'pkgname': 'libpam-modules-bin', 'pkgver': '1.1.8-1ubuntu2.2'},
    {'osver': '14.04', 'pkgname': 'libpam-runtime', 'pkgver': '1.1.8-1ubuntu2.2'},
    {'osver': '14.04', 'pkgname': 'libpam0g', 'pkgver': '1.1.8-1ubuntu2.2'},
    {'osver': '14.04', 'pkgname': 'libpam0g-dev', 'pkgver': '1.1.8-1ubuntu2.2'}
];

var flag = 0;
foreach var 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)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libpam-cracklib / libpam-modules / libpam-modules-bin / etc');
}