Ubuntu 16.04 LTS / 18.04 LTS : librsvg regression (USN-4436-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4436-2. 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(139180);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2017-11464", "CVE-2019-20446");
  script_xref(name:"USN", value:"4436-2");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS : librsvg regression (USN-4436-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"USN-4436-1 fixed a vulnerability in librsvg. The upstream fix caused a
regression when parsing certain SVG files. This update backs out the
fix pending further investigation.

It was discovered that librsvg incorrectly handled parsing certain SVG
files. A remote attacker could possibly use this issue to cause
librsvg to crash, resulting in a denial of service. This issue only
affected Ubuntu 16.04 LTS. (CVE-2017-11464) It was discovered that
librsvg incorrectly handled parsing certain SVG files with nested
patterns. A remote attacker could possibly use this issue to cause
librsvg to consume resources and crash, resulting in a denial of
service. (CVE-2019-20446).

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-4436-2");
  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:P/A:P");
  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:N/UI:R/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:"cvss_score_source", value:"CVE-2017-11464");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librsvg2-2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librsvg2-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librsvg2-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librsvg2-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gir1.2-rsvg-2.0");
  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) 2020-2023 Canonical, Inc. / NASL script (C) 2020-2023 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 (! ('16.04' >< os_release || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04', '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': '16.04', 'pkgname': 'gir1.2-rsvg-2.0', 'pkgver': '2.40.13-3ubuntu0.2'},
    {'osver': '16.04', 'pkgname': 'librsvg2-2', 'pkgver': '2.40.13-3ubuntu0.2'},
    {'osver': '16.04', 'pkgname': 'librsvg2-bin', 'pkgver': '2.40.13-3ubuntu0.2'},
    {'osver': '16.04', 'pkgname': 'librsvg2-common', 'pkgver': '2.40.13-3ubuntu0.2'},
    {'osver': '16.04', 'pkgname': 'librsvg2-dev', 'pkgver': '2.40.13-3ubuntu0.2'},
    {'osver': '18.04', 'pkgname': 'gir1.2-rsvg-2.0', 'pkgver': '2.40.20-2ubuntu0.2'},
    {'osver': '18.04', 'pkgname': 'librsvg2-2', 'pkgver': '2.40.20-2ubuntu0.2'},
    {'osver': '18.04', 'pkgname': 'librsvg2-bin', 'pkgver': '2.40.20-2ubuntu0.2'},
    {'osver': '18.04', 'pkgname': 'librsvg2-common', 'pkgver': '2.40.20-2ubuntu0.2'},
    {'osver': '18.04', 'pkgname': 'librsvg2-dev', 'pkgver': '2.40.20-2ubuntu0.2'}
];

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, 'gir1.2-rsvg-2.0 / librsvg2-2 / librsvg2-bin / librsvg2-common / etc');
}