Ubuntu 14.04 LTS : linux-lts-wily vulnerabilities (USN-2853-1)

2015-12-21T00:00:00
ID UBUNTU_USN-2853-1.NASL
Type nessus
Reporter Ubuntu Security Notice (C) 2015-2019 Canonical, Inc. / NASL script (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-02-02T00:00:00

Description

Felix Wilhelm discovered a race condition in the Xen paravirtualized drivers which can cause double fetch vulnerabilities. An attacker in the paravirtualized guest could exploit this flaw to cause a denial of service (crash the host) or potentially execute arbitrary code on the host. (CVE-2015-8550)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not perform sanity checks on the device

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2853-1. 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(87536);
  script_version("2.13");
  script_cvs_date("Date: 2019/09/18 12:31:45");

  script_cve_id("CVE-2015-8550", "CVE-2015-8551", "CVE-2015-8552");
  script_xref(name:"USN", value:"2853-1");

  script_name(english:"Ubuntu 14.04 LTS : linux-lts-wily vulnerabilities (USN-2853-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Felix Wilhelm discovered a race condition in the Xen paravirtualized
drivers which can cause double fetch vulnerabilities. An attacker in
the paravirtualized guest could exploit this flaw to cause a denial of
service (crash the host) or potentially execute arbitrary code on the
host. (CVE-2015-8550)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform sanity checks on the device's state. An attacker could exploit
this flaw to cause a denial of service (NULL dereference) on the host.
(CVE-2015-8551)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform sanity checks on the device's state. An attacker could exploit
this flaw to cause a denial of service by flooding the logging system
with WARN() messages causing the initial domain to exhaust disk space.
(CVE-2015-8552)

Jann Horn discovered a ptrace issue with user namespaces in the Linux
kernel. The namespace owner could potentially exploit this flaw by
ptracing a root owned process entering the user namespace to elevate
its privileges and potentially gain access outside of the namespace.
(http://bugs.launchpad.net/bugs/1527374)

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://usn.ubuntu.com/2853-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected linux-image-4.2-generic,
linux-image-4.2-generic-lpae and / or linux-image-4.2-lowlatency
packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:P/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-lowlatency");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/04/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/12/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/12/21");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2015-2019 Canonical, Inc. / NASL script (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl", "linux_alt_patch_detect.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("ksplice.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(14\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Ubuntu", cpu);

if (get_one_kb_item("Host/ksplice/kernel-cves"))
{
  rm_kb_item(name:"Host/uptrack-uname-r");
  cve_list = make_list("CVE-2015-8550", "CVE-2015-8551", "CVE-2015-8552");
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "KSplice hotfix for USN-2853-1");
  }
  else
  {
    _ubuntu_report = ksplice_reporting_text();
  }
}

flag = 0;

if (ubuntu_check(osver:"14.04", pkgname:"linux-image-4.2.0-22-generic", pkgver:"4.2.0-22.27~14.04.1")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"linux-image-4.2.0-22-generic-lpae", pkgver:"4.2.0-22.27~14.04.1")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"linux-image-4.2.0-22-lowlatency", pkgver:"4.2.0-22.27~14.04.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "linux-image-4.2-generic / linux-image-4.2-generic-lpae / etc");
}