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nessusUbuntu Security Notice (C) 2016-2023 Canonical, Inc. / NASL script (C) 2016-2023 and is owned by Tenable, Inc. or an Affiliate thereof.UBUNTU_USN-3061-1.NASL
HistoryAug 16, 2016 - 12:00 a.m.

Ubuntu 14.04 LTS / 16.04 LTS : OpenSSH vulnerabilities (USN-3061-1)

2016-08-1600:00:00
Ubuntu Security Notice (C) 2016-2023 Canonical, Inc. / NASL script (C) 2016-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
123

Eddie Harari discovered that OpenSSH incorrectly handled password hashing when authenticating non-existing users. A remote attacker could perform a timing attack and enumerate valid users.
(CVE-2016-6210)

Tomas Kuthan, Andres Rojas, and Javier Nieto discovered that OpenSSH did not limit password lengths. A remote attacker could use this issue to cause OpenSSH to consume resources, leading to a denial of service.
(CVE-2016-6515).

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.

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3061-1. 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(92985);
  script_version("2.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/23");

  script_cve_id("CVE-2016-6210", "CVE-2016-6515");
  script_xref(name:"USN", value:"3061-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : OpenSSH vulnerabilities (USN-3061-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Eddie Harari discovered that OpenSSH incorrectly handled password
hashing when authenticating non-existing users. A remote attacker
could perform a timing attack and enumerate valid users.
(CVE-2016-6210)

Tomas Kuthan, Andres Rojas, and Javier Nieto discovered that OpenSSH
did not limit password lengths. A remote attacker could use this issue
to cause OpenSSH to consume resources, leading to a denial of service.
(CVE-2016-6515).

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-3061-1");
  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:N");
  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:H/I:N/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-2016-6210");

  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:"2016/08/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/08/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/08/16");

  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) 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 || '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': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'openssh-server', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'ssh', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '14.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:6.6p1-2ubuntu2.8'},
    {'osver': '16.04', 'pkgname': 'openssh-client', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'openssh-client-ssh1', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'openssh-client-udeb', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'openssh-server', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'openssh-server-udeb', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'openssh-sftp-server', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'ssh', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'ssh-askpass-gnome', 'pkgver': '1:7.2p2-4ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'ssh-krb5', 'pkgver': '1:7.2p2-4ubuntu2.1'}
];

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');
}