Vulnerabilities > CVE-2015-4692 - Denial of Service vulnerability in Linux Kernel KVM 'kvm_apic_has_events()' Function

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2683-1. 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(84984);
  script_version("2.10");
  script_cvs_date("Date: 2019/09/18 12:31:44");

  script_cve_id("CVE-2015-4692", "CVE-2015-4700", "CVE-2015-5364", "CVE-2015-5366");
  script_xref(name:"USN", value:"2683-1");

  script_name(english:"Ubuntu 14.04 LTS : linux-lts-vivid vulnerabilities (USN-2683-1)");
  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:
"A flaw was discovered in the kvm (kernel virtual machine) subsystem's
kvm_apic_has_events function. A unprivileged local user could exploit
this flaw to cause a denial of service (system crash). (CVE-2015-4692)

Daniel Borkmann reported a kernel crash in the Linux kernel's BPF
filter JIT optimization. A local attacker could exploit this flaw to
cause a denial of service (system crash). (CVE-2015-4700)

A flaw was discovered in how the Linux kernel handles invalid UDP
checksums. A remote attacker could exploit this flaw to cause a denial
of service using a flood of UDP packets with invalid checksums.
(CVE-2015-5364)

A flaw was discovered in how the Linux kernel handles invalid UDP
checksums. A remote attacker can cause a denial of service against
applications that use epoll by injecting a single packet with an
invalid checksum. (CVE-2015-5366).

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/2683-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected linux-image-3.19-generic,
linux-image-3.19-generic-lpae and / or linux-image-3.19-lowlatency
packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/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-3.19-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.19-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.19-lowlatency");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/07/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/07/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/07/24");
  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-2015-4692", "CVE-2015-4700", "CVE-2015-5364", "CVE-2015-5366");
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "KSplice hotfix for USN-2683-1");
  }
  else
  {
    _ubuntu_report = ksplice_reporting_text();
  }
}

flag = 0;

if (ubuntu_check(osver:"14.04", pkgname:"linux-image-3.19.0-23-generic", pkgver:"3.19.0-23.24~14.04.1")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"linux-image-3.19.0-23-generic-lpae", pkgver:"3.19.0-23.24~14.04.1")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"linux-image-3.19.0-23-lowlatency", pkgver:"3.19.0-23.24~14.04.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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-3.19-generic / linux-image-3.19-generic-lpae / etc");
}