Oracle Linux 8 : varnish:6 (ELSA-2021-2988)

2021-08-03T00:00:00
ID ORACLELINUX_ELSA-2021-2988.NASL
Type nessus
Reporter This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2021-08-10T00:00:00

Description

The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2021-2988 advisory.

  • Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8. (CVE-2021-36740)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

                                        
                                            #%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2021-2988.
##

include('deprecated_nasl_level.inc');

include('compat.inc');

if (description)
{
  script_id(152184);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/08/10");

  script_cve_id("CVE-2021-36740");

  script_name(english:"Oracle Linux 8 : varnish:6 (ELSA-2021-2988)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the
ELSA-2021-2988 advisory.

  - Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large
    Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and
    Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8. (CVE-2021-36740)

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://linux.oracle.com/errata/ELSA-2021-2988.html");
  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:L/I:L/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-2021-36740");

  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:"2021/07/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/08/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/08/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:varnish");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:varnish-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:varnish-docs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:varnish-modules");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Oracle Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 8', 'Oracle Linux ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var module_ver = get_kb_item('Host/RedHat/appstream/varnish');
if (isnull(module_ver)) audit(AUDIT_PACKAGE_NOT_INSTALLED, 'Module varnish:6');
if ('6' >!< module_ver) audit(AUDIT_PACKAGE_NOT_AFFECTED, 'Module varnish:' + module_ver);

var appstreams = {
    'varnish:6': [
      {'reference':'varnish-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-devel-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-devel-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-docs-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-docs-6.0.6-2.module+el8.4.0+20258+f99218b2.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-modules-0.15.0-5.module+el8.3.0+7653+45014445', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'varnish-modules-0.15.0-5.module+el8.3.0+7653+45014445', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
    ]
};

var flag = 0;
var appstreams_found = 0;
foreach module (keys(appstreams)) {
  var appstream = NULL;
  var appstream_name = NULL;
  var appstream_version = NULL;
  var appstream_split = split(module, sep:':', keep:FALSE);
  if (!empty_or_null(appstream_split)) {
    appstream_name = appstream_split[0];
    appstream_version = appstream_split[1];
    if (!empty_or_null(appstream_name)) appstream = get_one_kb_item('Host/RedHat/appstream/' + appstream_name);
  }
  if (!empty_or_null(appstream) && appstream_version == appstream || appstream_name == 'all') {
    appstreams_found++;
    foreach package_array ( appstreams[module] ) {
      var reference = NULL;
      var release = NULL;
      var sp = NULL;
      var cpu = NULL;
      var el_string = NULL;
      var rpm_spec_vers_cmp = NULL;
      var epoch = NULL;
      var allowmaj = NULL;
      if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
      if (!empty_or_null(package_array['release'])) release = 'EL' + package_array['release'];
      if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
      if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
      if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
      if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
      if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
      if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
      if (reference && release) {
        if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
      }
    }
  }
}

if (!appstreams_found) audit(AUDIT_PACKAGE_NOT_INSTALLED, 'Module varnish:6');

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'varnish / varnish-devel / varnish-docs / etc');
}