Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS : Varnish Cache vulnerabilities (USN-5474-1)

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5474-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(161982);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2019-20637",
    "CVE-2020-11653",
    "CVE-2021-36740",
    "CVE-2022-23959"
  );
  script_xref(name:"USN", value:"5474-1");

  script_name(english:"Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS : Varnish Cache vulnerabilities (USN-5474-1)");

  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 18.04 LTS / 20.04 LTS / 22.04 LTS host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-5474-1 advisory.

    It was dicovered that Varnish Cache did not clear a pointer between the handling of one client request and
    the next request within the same connection. A remote attacker could possibly use this issue to obtain
    sensitive information. (CVE-2019-20637)

    It was discovered that Varnish Cache could have an assertion failure when a TLS termination proxy uses
    PROXY version 2. A remote attacker could possibly use this issue to restart the daemon and cause a
    performance loss. (CVE-2020-11653)

    It was discovered that Varnish Cache allowed request smuggling and VCL authorization bypass via a large
    Content-Length header for a POST request. A remote attacker could possibly use this issue to obtain
    sensitive information. (CVE-2021-36740)

    It was discovered that Varnish Cache allowed request smuggling for HTTP/1 connections. A remote attacker
    could possibly use this issue to obtain sensitive information. (CVE-2022-23959)

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-5474-1");
  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:N");
  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:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2022-23959");

  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:"2020/04/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/06/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/06/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvarnishapi-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvarnishapi1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvarnishapi2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:varnish");
  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) 2022-2024 Canonical, Inc. / NASL script (C) 2022-2024 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 (! ('18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04 / 20.04 / 22.04', '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': '18.04', 'pkgname': 'libvarnishapi-dev', 'pkgver': '5.2.1-1ubuntu0.1'},
    {'osver': '18.04', 'pkgname': 'libvarnishapi1', 'pkgver': '5.2.1-1ubuntu0.1'},
    {'osver': '18.04', 'pkgname': 'varnish', 'pkgver': '5.2.1-1ubuntu0.1'},
    {'osver': '20.04', 'pkgname': 'libvarnishapi-dev', 'pkgver': '6.2.1-2ubuntu0.1'},
    {'osver': '20.04', 'pkgname': 'libvarnishapi2', 'pkgver': '6.2.1-2ubuntu0.1'},
    {'osver': '20.04', 'pkgname': 'varnish', 'pkgver': '6.2.1-2ubuntu0.1'},
    {'osver': '22.04', 'pkgname': 'libvarnishapi-dev', 'pkgver': '6.6.1-1ubuntu0.2'},
    {'osver': '22.04', 'pkgname': 'libvarnishapi2', 'pkgver': '6.6.1-1ubuntu0.2'},
    {'osver': '22.04', 'pkgname': 'varnish', 'pkgver': '6.6.1-1ubuntu0.2'}
];

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_WARNING,
    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, 'libvarnishapi-dev / libvarnishapi1 / libvarnishapi2 / varnish');
}