Ubuntu 16.04 LTS / 18.04 LTS : Squid vulnerabilities (USN-4446-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4446-1. 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(139313);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id(
    "CVE-2019-12520",
    "CVE-2019-12523",
    "CVE-2019-12524",
    "CVE-2019-18676"
  );
  script_xref(name:"USN", value:"4446-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS : Squid vulnerabilities (USN-4446-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Jeriko One discovered that Squid incorrectly handled caching certain
requests. A remote attacker could possibly use this issue to perform
cache-injection attacks or gain access to reverse proxy features such
as ESI. (CVE-2019-12520) Jeriko One and Kristoffer Danielsson
discovered that Squid incorrectly handled certain URN requests. A
remote attacker could possibly use this issue to bypass access checks.
(CVE-2019-12523) Jeriko One discovered that Squid incorrectly handled
URL decoding. A remote attacker could possibly use this issue to
bypass certain rule checks. (CVE-2019-12524) Jeriko One and Kristoffer
Danielsson discovered that Squid incorrectly handled input validation.
A remote attacker could use this issue to cause Squid to crash,
resulting in a denial of service. (CVE-2019-18676).

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-4446-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:"cvss_score_source", value:"CVE-2019-12524");

  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:"2019/11/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/08/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/08/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squid-cgi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squid-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squid-purge");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squid3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:squidclient");
  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:"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': 'squid', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '16.04', 'pkgname': 'squid-cgi', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '16.04', 'pkgname': 'squid-common', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '16.04', 'pkgname': 'squid-purge', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '16.04', 'pkgname': 'squid3', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '16.04', 'pkgname': 'squidclient', 'pkgver': '3.5.12-1ubuntu7.12'},
    {'osver': '18.04', 'pkgname': 'squid', 'pkgver': '3.5.27-1ubuntu1.7'},
    {'osver': '18.04', 'pkgname': 'squid-cgi', 'pkgver': '3.5.27-1ubuntu1.7'},
    {'osver': '18.04', 'pkgname': 'squid-common', 'pkgver': '3.5.27-1ubuntu1.7'},
    {'osver': '18.04', 'pkgname': 'squid-purge', 'pkgver': '3.5.27-1ubuntu1.7'},
    {'osver': '18.04', 'pkgname': 'squid3', 'pkgver': '3.5.27-1ubuntu1.7'},
    {'osver': '18.04', 'pkgname': 'squidclient', 'pkgver': '3.5.27-1ubuntu1.7'}
];

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_HOLE,
    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, 'squid / squid-cgi / squid-common / squid-purge / squid3 / etc');
}