Amazon Linux 2023 : nginx, nginx-all-modules, nginx-core (ALAS2023-2026-3263)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2023 Security Advisory ALAS2023-2026-3263.
##

include('compat.inc');

if (description)
{
  script_id(371840);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/25");

  script_cve_id(
    "CVE-2026-15176",
    "CVE-2026-93479",
    "CVE-2026-95101",
    "CVE-2026-97205",
    "CVE-2026-97629"
  );
  script_xref(name:"IAVA", value:"2026-A-1142");

  script_name(english:"Amazon Linux 2023 : nginx, nginx-all-modules, nginx-core (ALAS2023-2026-3263)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2023 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3263 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)

    A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and
    the root directive or access log format references the map's regex capture variables before referencing
    the map output variable. Alternatively, the same result could be achieved by using a non-cacheable
    variable in a string expression under certain conditions. 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-2026-93479)

    DescriptionNGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_v3_module module. When
    using HTTP/3 with

    proxy_request_buffering on directive, an unauthenticated attacker may be able to inject data in the
    proxied request.

    Impact

    This vulnerability may allow remote attackers to

    inject data in the proxied request.  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-2026-95101)

    NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_core_module module. When
    asynchronous file I/O (AIO) is enabled in certain configurations, processing a Server Side Includes (SSI)
    page containing include virtual commands may trigger a Use-After-Free (UAF) in the NGINX worker process.
    This may cause memory corruption or a worker process crash. 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, corrupt its memory, or possibly trigger 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-2026-97205)

    DescriptionWhen NGINX Plus or NGINX Open Source is configured with ssl_session_cache

    shared:name:size

    without an explicit ssl_session_ticket_key file directives to automatically rotate SSL session ticket
    keys, a remote unauthenticated attacker is able to forge client SSL sessions

    in a non-deterministic manner that is beyond the attacker's control. An attacker could leverage this
    vulnerability to bypass verification of client certificates.

    Impact

    This vulnerability can lead to the exposure of resources or functionality to unintended actors, possibly
    providing attackers with access to sensitive information. 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-2026-97629)

Tenable has extracted the preceding description block directly from the tested product 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://alas.aws.amazon.com//AL2023/ALAS2023-2026-3263.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-15176.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-93479.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-95101.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-97205.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-97629.html");
  script_set_attribute(attribute:"solution", value:
"Run 'dnf update nginx --releasever 2023.12.20261026' or
  or 'dnf update --advisory ALAS2023-2026-3263 --releasever 2023.12.20261026' to update your system.");
  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: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:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/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:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-97205");

  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:"2026/10/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-all-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-core-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-filesystem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-image-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-image-filter-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-perl-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-xslt-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-http-xslt-filter-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-mail");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-mail-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-stream");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nginx-mod-stream-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2023");
  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:"Amazon 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/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}

include("rpm2.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "-2023")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2023", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'nginx-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-all-modules-1.30.6-1.amzn2023.0.1', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-core-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-core-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-core-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-core-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-debugsource-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-debugsource-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-filesystem-1.30.6-1.amzn2023.0.1', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-devel-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-devel-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-image-filter-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-image-filter-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-image-filter-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-image-filter-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-perl-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-perl-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-perl-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-perl-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-xslt-filter-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-xslt-filter-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-xslt-filter-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-http-xslt-filter-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-mail-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-mail-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-mail-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-mail-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-stream-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-stream-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-stream-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'aarch64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'nginx-mod-stream-debuginfo-1.30.6-1.amzn2023.0.1', 'cpu':'x86_64', 'release':'AL-2023', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  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;
  var exists_check = NULL;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 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 (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
    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, 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 / etc");
}