Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : OpenSSH vulnerability (USN-3885-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3885-2. 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(122610);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id("CVE-2019-6111");
  script_xref(name:"USN", value:"3885-2");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : OpenSSH vulnerability (USN-3885-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"USN-3885-1 fixed vulnerabilities in OpenSSH. It was discovered that
the fix for CVE-2019-6111 turned out to be incomplete. This update
fixes the problem.

Original advisory details :

Harry Sintonen discovered multiple issues in the OpenSSH scp utility.
If a user or automated system were tricked into connecting to an
untrusted server, a remote attacker could possibly use these issues to
write to arbitrary files, change directory permissions, and spoof
client output.

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-3885-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/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:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-6111");

  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:"2019/01/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/05");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:"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:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  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) 2019-2023 Canonical, Inc. / NASL script (C) 2019-2023 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 || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04', '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': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'openssh-server', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'ssh', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '14.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:6.6p1-2ubuntu2.13'},
    {'osver': '16.04', 'pkgname': 'openssh-client', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-client-ssh1', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-server', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'ssh', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:7.2p2-4ubuntu2.8'},
    {'osver': '18.04', 'pkgname': 'openssh-client', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'openssh-server', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'ssh', 'pkgver': '1:7.6p1-4ubuntu0.3'},
    {'osver': '18.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:7.6p1-4ubuntu0.3'}
];

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