Ubuntu 14.04 LTS / 16.04 LTS : Linux kernel vulnerabilities (USN-3641-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3641-1. 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(109650);
  script_version("1.15");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id("CVE-2018-1000199", "CVE-2018-1087", "CVE-2018-8897");
  script_xref(name:"USN", value:"3641-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : Linux kernel vulnerabilities (USN-3641-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS / 16.04 LTS host has a package installed that is affected by multiple vulnerabilities as
referenced in the USN-3641-1 advisory.

  - The Linux Kernel version 3.18 contains a dangerous feature vulnerability in modify_user_hw_breakpoint()
    that can result in crash and possibly memory corruption. This attack appear to be exploitable via local
    code execution and the ability to use ptrace. This vulnerability appears to have been fixed in git commit
    f67b15037a7a50c57f72e69a6d59941ad90a0f0f. (CVE-2018-1000199)

  - kernel KVM before versions kernel 4.16, kernel 4.16-rc7, kernel 4.17-rc1, kernel 4.17-rc2 and kernel
    4.17-rc3 is vulnerable to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered
    after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the
    processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction
    after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest
    or, potentially, escalate their privileges in the guest. (CVE-2018-1087)

  - A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's
    Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in
    unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for
    example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel
    crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and
    single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A;
    section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS
    instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF)
    system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS
    instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating
    system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels
    may not expect this order of events and may therefore experience unexpected behavior when it occurs.
    (CVE-2018-8897)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-3641-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/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:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-8897");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Microsoft Windows POP/MOV SS Local Privilege Elevation Vulnerability');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/05/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/05/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-lowlatency");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-powerpc-e500");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-powerpc-e500mc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-powerpc-smp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-powerpc64-emb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.13.0-147-powerpc64-smp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-1015-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-1016-azure");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-1026-oem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-41-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-41-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.13.0-41-lowlatency");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1019-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1023-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1057-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1089-raspi2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1092-snapdragon");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-lowlatency");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-powerpc-e500mc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-powerpc-smp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-powerpc64-emb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-124-powerpc64-smp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-9027-euclid");
  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:"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) 2018-2024 Canonical, Inc. / NASL script (C) 2018-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  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('debian_package.inc');
include('ksplice.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 kernel_mappings = {
  '14.04': {
    '3.13.0': {
      'generic': '3.13.0-147',
      'generic-lpae': '3.13.0-147',
      'lowlatency': '3.13.0-147',
      'powerpc-e500': '3.13.0-147',
      'powerpc-e500mc': '3.13.0-147',
      'powerpc-smp': '3.13.0-147',
      'powerpc64-emb': '3.13.0-147',
      'powerpc64-smp': '3.13.0-147'
    },
    '4.4.0': {
      'generic': '4.4.0-124',
      'generic-lpae': '4.4.0-124',
      'lowlatency': '4.4.0-124',
      'powerpc-e500mc': '4.4.0-124',
      'powerpc-smp': '4.4.0-124',
      'powerpc64-emb': '4.4.0-124',
      'powerpc64-smp': '4.4.0-124',
      'aws': '4.4.0-1019'
    }
  },
  '16.04': {
    '4.13.0': {
      'generic': '4.13.0-41',
      'generic-lpae': '4.13.0-41',
      'lowlatency': '4.13.0-41',
      'gcp': '4.13.0-1015',
      'azure': '4.13.0-1016',
      'oem': '4.13.0-1026'
    },
    '4.4.0': {
      'generic': '4.4.0-124',
      'generic-lpae': '4.4.0-124',
      'lowlatency': '4.4.0-124',
      'powerpc-e500mc': '4.4.0-124',
      'powerpc-smp': '4.4.0-124',
      'powerpc64-emb': '4.4.0-124',
      'powerpc64-smp': '4.4.0-124',
      'kvm': '4.4.0-1023',
      'aws': '4.4.0-1057',
      'raspi2': '4.4.0-1089',
      'snapdragon': '4.4.0-1092',
      'euclid': '4.4.0-9027'
    }
  }
};

var host_kernel_release = get_kb_item('Host/uptrack-uname-r');
if (empty_or_null(host_kernel_release)) host_kernel_release = get_kb_item_or_exit('Host/uname-r');
var host_kernel_base_version = get_kb_item_or_exit('Host/Debian/kernel-base-version');
var host_kernel_type = get_kb_item_or_exit('Host/Debian/kernel-type');
if(empty_or_null(kernel_mappings[os_release][host_kernel_base_version][host_kernel_type])) audit(AUDIT_INST_VER_NOT_VULN, 'kernel ' + host_kernel_release);

var extra = '';
var kernel_fixed_version = kernel_mappings[os_release][host_kernel_base_version][host_kernel_type] + "-" + host_kernel_type;
if (deb_ver_cmp(ver1:host_kernel_release, ver2:kernel_fixed_version) < 0)
{
  extra = extra + 'Running Kernel level of ' + host_kernel_release + ' does not meet the minimum fixed level of ' + kernel_fixed_version + ' for this advisory.\n\n';
}
  else
{
  audit(AUDIT_PATCH_INSTALLED, 'Kernel package for USN-3641-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2018-1087', 'CVE-2018-8897', 'CVE-2018-1000199');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-3641-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}