Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : libseccomp vulnerability (USN-4001-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4001-1. 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(125624);
  script_version("1.3");
  script_cvs_date("Date: 2020/01/13");

  script_cve_id("CVE-2019-9893");
  script_xref(name:"USN", value:"4001-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : libseccomp vulnerability (USN-4001-1)");
  script_summary(english:"Checks dpkg output for updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Ubuntu host is missing a security-related patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Jann Horn discovered that libseccomp did not correctly generate 64-bit
syscall argument comparisons with arithmetic operators (LT, GT, LE,
GE). An attacker could use this to bypass intended access restrictions
for argument-filtered system calls.

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/4001-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected libseccomp2 package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libseccomp2");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:19.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/03/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/31");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.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:"^(16\.04|18\.04|18\.10|19\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 16.04 / 18.04 / 18.10 / 19.04", "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);

flag = 0;

if (ubuntu_check(osver:"16.04", pkgname:"libseccomp2", pkgver:"2.4.1-0ubuntu0.16.04.2")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libseccomp2", pkgver:"2.4.1-0ubuntu0.18.04.2")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libseccomp2", pkgver:"2.4.1-0ubuntu0.18.10.3")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libseccomp2", pkgver:"2.4.1-0ubuntu0.19.04.3")) 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, "libseccomp2");
}