CentOS Linux 6 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-filesystem / nginx-mod-http-geoip / etc Multiple Vulnerabilities (CENTOS6:CLSA-2026:1776791510)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(352522);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id(
    "CVE-2017-7529",
    "CVE-2018-16843",
    "CVE-2018-16844",
    "CVE-2019-9511",
    "CVE-2019-9513"
  );
  script_xref(name:"CLSA", value:"2026:1776791510");
  script_xref(name:"CEA-ID", value:"CEA-2019-0643");

  script_name(english:"CentOS Linux 6 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-filesystem / nginx-mod-http-geoip / etc Multiple Vulnerabilities (CENTOS6:CLSA-2026:1776791510)");

  script_set_attribute(attribute:"synopsis", value:
"The CentOS Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The CentOS Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the
TuxCare CENTOS6:CLSA-2026:1776791510 advisory.

  - Nginx versions since 0.5.6 up to and including 1.13.2 are vulnerable to integer overflow vulnerability in
    nginx range filter module resulting into leak of potentially sensitive information triggered by specially
    crafted request. (CVE-2017-7529)

  - nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow
    for excessive memory consumption. This issue affects nginx compiled with the ngx_http_v2_module (not
    compiled by default) if the 'http2' option of the 'listen' directive is used in a configuration file.
    (CVE-2018-16843)

  - nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow
    for excessive CPU usage. This issue affects nginx compiled with the ngx_http_v2_module (not compiled by
    default) if the 'http2' option of the 'listen' directive is used in a configuration file. (CVE-2018-16844)

  - Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization
    manipulation, potentially leading to a denial of service. The attacker requests a large amount of data
    from a specified resource over multiple streams. They manipulate window size and stream priority to force
    the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can
    consume excess CPU, memory, or both. (CVE-2019-9511)

  - Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service.
    The attacker creates multiple request streams and continually shuffles the priority of the streams in a
    way that causes substantial churn to the priority tree. This can consume excess CPU. (CVE-2019-9513)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/centos6els/advisories/2026/clsa-2026_1776791510.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c0c1241a");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1776791510");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory CENTOS6:CLSA-2026:1776791510.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-7529");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/OS/extended-third-party", "Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/rpm-list");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'CentOS Linux' >!< os_product) audit(AUDIT_OS_NOT, 'CentOS Linux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'CentOS Linux');
if (! preg(pattern:"^6([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'CentOS Linux 6', 'CentOS Linux ' + os_version);

if (!get_kb_item('Host/CentOS/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) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'CentOS Linux', cpu);


var constraints = [
  {
    'release': '6',
    'pkgs': [
      {'reference':'nginx-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-all-modules-1.10.3-4.el6.tuxcare.els7', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-filesystem-1.10.3-4.el6.tuxcare.els7', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-http-geoip-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-http-image-filter-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-http-perl-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-http-xslt-filter-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-mail-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'nginx-mod-stream-1.10.3-4.el6.tuxcare.els7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}


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 / nginx-mod-http-geoip / etc');
}