Ubuntu 14.04 LTS / 16.04 LTS : OpenSSH vulnerabilities (USN-3538-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3538-1. 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(106266);
  script_version("3.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id(
    "CVE-2016-10009",
    "CVE-2016-10010",
    "CVE-2016-10011",
    "CVE-2016-10012",
    "CVE-2017-15906"
  );
  script_xref(name:"USN", value:"3538-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : OpenSSH vulnerabilities (USN-3538-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Jann Horn discovered that OpenSSH incorrectly loaded PKCS#11 modules
from untrusted directories. A remote attacker could possibly use this
issue to execute arbitrary PKCS#11 modules. This issue only affected
Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-10009)

Jann Horn discovered that OpenSSH incorrectly handled permissions on
Unix-domain sockets when privilege separation is disabled. A local
attacker could possibly use this issue to gain privileges. This issue
only affected Ubuntu 16.04 LTS. (CVE-2016-10010)

Jann Horn discovered that OpenSSH incorrectly handled certain buffer
memory operations. A local attacker could possibly use this issue to
obtain sensitive information. This issue only affected Ubuntu 14.04
LTS and Ubuntu 16.04 LTS. (CVE-2016-10011)

Guido Vranken discovered that OpenSSH incorrectly handled certain
shared memory manager operations. A local attacker could possibly use
issue to gain privileges. This issue only affected Ubuntu 14.04 LTS
and Ubuntu 16.04 LTS. This issue only affected Ubuntu 14.04 LTS and
Ubuntu 16.04 LTS. (CVE-2016-10012)

Michal Zalewski discovered that OpenSSH incorrectly prevented write
operations in readonly mode. A remote attacker could possibly use this
issue to create zero-length files, leading to a denial of service.
(CVE-2017-15906).

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-3538-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-2016-10009");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2016-10012");

  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:"2017/01/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-server-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-sftp-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ssh-askpass-gnome");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ssh-krb5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-client-ssh1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-client-udeb");
  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) 2018-2023 Canonical, Inc. / NASL script (C) 2018-2023 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 || '16.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04', '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': 'openssh-client', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'openssh-server', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'ssh', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '14.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:6.6p1-2ubuntu2.10'},
    {'osver': '16.04', 'pkgname': 'openssh-client', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'openssh-client-ssh1', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'openssh-server', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'ssh', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:7.2p2-4ubuntu2.4'},
    {'osver': '16.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:7.2p2-4ubuntu2.4'}
];

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_HOLE,
    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, 'openssh-client / openssh-client-ssh1 / openssh-client-udeb / etc');
}