Oracle Linux 8 : nginx:1.16 (ELSA-2021-2290)

#%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-2021-2290.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(150496);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/11/01");

  script_cve_id("CVE-2021-23017");
  script_xref(name:"IAVB", value:"2021-B-0031");

  script_name(english:"Oracle Linux 8 : nginx:1.16 (ELSA-2021-2290)");

  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-2021-2290 advisory.

    [1.16.1-2.0.1.1]
    - Remove Red Hat references [Orabug: 29498217]

    [1:1.16.1-2.1]
    - Resolves: #1963174 - CVE-2021-23017 nginx:1.16/nginx: Off-by-one in
      ngx_resolver_copy() when labels are followed by a pointer to a root
      domain name

Tenable has extracted the preceding description block directly from the Oracle Linux 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://linux.oracle.com/errata/ELSA-2021-2290.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-23017");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/05/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/06/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/06/10");

  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:nginx");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-all-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-filesystem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-image-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-xslt-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-mail");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-stream");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2024 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('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 os_release = get_kb_item("Host/RedHat/release");
if (isnull(os_release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
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/nginx');
if (isnull(module_ver)) audit(AUDIT_PACKAGE_NOT_INSTALLED, 'Module nginx:1.16');
if ('1.16' >!< module_ver) audit(AUDIT_PACKAGE_NOT_AFFECTED, 'Module nginx:' + module_ver);

var appstreams = {
    'nginx:1.16': [
      {'reference':'nginx-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-all-modules-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-filesystem-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-image-filter-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-perl-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-xslt-filter-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-mail-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-stream-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-all-modules-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-filesystem-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-image-filter-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-perl-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-xslt-filter-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-mail-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-stream-1.16.1-2.0.1.module+el8.4.0+20188+a733e426.1', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
    ]
};

var flag = 0;
var appstreams_found = 0;
foreach var 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 var 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 nginx:1.16');

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, 'nginx / nginx-all-modules / nginx-filesystem / etc');
}