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("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  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:
"The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as
referenced in the USN-4446-1 advisory.

    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)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

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-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) 2020-2024 Canonical, Inc. / NASL script (C) 2020-2024 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 var 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)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  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');
}