AlmaLinux 9.2 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-core / nginx-filesystem / etc (ALMALINUX9.2:CLSA-2026:1792170794)

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

include('compat.inc');

if (description)
{
  script_id(366642);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/16");

  script_cve_id("CVE-2026-15176");
  script_xref(name:"CLSA", value:"2026:1792170794");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-core / nginx-filesystem / etc (ALMALINUX9.2:CLSA-2026:1792170794)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.2 host has packages installed that are affected by a vulnerability as referenced in the TuxCare
ALMALINUX9.2:CLSA-2026:1792170794 advisory.

  - A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the
    alias directive together with rewrite and a set or return directive referencing the $request_filename
    variable. Alternatively, the same result could be achieved when the $request_filename variable is used in
    an access log format directive. An unauthenticated attacker along with conditions beyond their control can
    exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the
    NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with
    Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Impact: This
    vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to
    possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only.
    Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
    (CVE-2026-15176)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/almalinux9.2esu/advisories/2026/clsa-2026_1792170794.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?45bc320c");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1792170794");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1792170794.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/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:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-15176");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_severity", value:"Critical");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/16");

  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:"Alma Linux 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/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  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) || 'AlmaLinux' >!< os_product) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
if (! preg(pattern:"^9.2([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.2', 'AlmaLinux ' + os_version);

if (!get_kb_item('Host/AlmaLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'nginx-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-all-modules-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-core-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-core-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-core-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-filesystem-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-devel-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-devel-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-devel-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-image-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-image-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-image-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-perl-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-perl-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-perl-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-xslt-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-xslt-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-http-xslt-filter-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-mail-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-mail-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-mail-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-stream-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'aarch64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-stream-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'nginx-mod-stream-1.20.1-14.el9_2.1.alma.1.tuxcare.els15', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
    ]
  }
];

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_HOLE,
      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-core / nginx-filesystem / etc');
}