Ubuntu 16.04 LTS / 18.04 LTS : Squid regression (USN-4446-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4446-2. 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(140028);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");
  script_xref(name:"USN", value:"4446-2");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS : Squid regression (USN-4446-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by a vulnerability as referenced
in the USN-4446-2 advisory.

    USN-4446-1 fixed vulnerabilities in Squid. The update introduced a regression when using Squid with the
    icap or ecap protocols. This update fixes the problem.

    We apologize for the inconvenience.

    Original advisory details:

    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 this issue 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-4446-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_attribute(attribute:"risk_factor", value:"High");

  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:"2020/08/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/08/28");

  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': '3.5.12-1ubuntu7.13'},
    {'osver': '16.04', 'pkgname': 'squid-cgi', 'pkgver': '3.5.12-1ubuntu7.13'},
    {'osver': '16.04', 'pkgname': 'squid-common', 'pkgver': '3.5.12-1ubuntu7.13'},
    {'osver': '16.04', 'pkgname': 'squid-purge', 'pkgver': '3.5.12-1ubuntu7.13'},
    {'osver': '16.04', 'pkgname': 'squid3', 'pkgver': '3.5.12-1ubuntu7.13'},
    {'osver': '16.04', 'pkgname': 'squidclient', 'pkgver': '3.5.12-1ubuntu7.13'},
    {'osver': '18.04', 'pkgname': 'squid', 'pkgver': '3.5.27-1ubuntu1.8'},
    {'osver': '18.04', 'pkgname': 'squid-cgi', 'pkgver': '3.5.27-1ubuntu1.8'},
    {'osver': '18.04', 'pkgname': 'squid-common', 'pkgver': '3.5.27-1ubuntu1.8'},
    {'osver': '18.04', 'pkgname': 'squid-purge', 'pkgver': '3.5.27-1ubuntu1.8'},
    {'osver': '18.04', 'pkgname': 'squid3', 'pkgver': '3.5.27-1ubuntu1.8'},
    {'osver': '18.04', 'pkgname': 'squidclient', 'pkgver': '3.5.27-1ubuntu1.8'}
];

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');
}