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("2.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2013-7041", "CVE-2014-2583", "CVE-2015-3238");
  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:
"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.

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).

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-2935-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/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:L/I:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2015-3238");

  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:"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) 2016-2023 Canonical, Inc. / NASL script (C) 2016-2023 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 (! ('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 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, 'libpam-cracklib / libpam-modules / libpam-modules-bin / etc');
}