Debian dsa-6496 : libnginx-mod-http-geoip - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dsa-6496. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(345000);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/12");

  script_cve_id("CVE-2026-42533", "CVE-2026-56434", "CVE-2026-60005");
  script_xref(name:"IAVA", value:"2026-A-0754");

  script_name(english:"Debian dsa-6496 : libnginx-mod-http-geoip - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dsa-6496 advisory.

    - -------------------------------------------------------------------------
    Debian Security Advisory DSA-6496-1                   [email protected]
    https://www.debian.org/security/                                  Aron Xu
    September 12, 2026                    https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : nginx
    CVE ID         : CVE-2026-42533 CVE-2026-56434 CVE-2026-60005

    Multiple vulnerabilities were discovered in nginx, a high-performance web
    and reverse proxy server, which may result in denial of service, memory
    disclosure or potentially the execution of arbitrary code.

    CVE-2026-42533

        A heap buffer overflow was discovered in the nginx script engine. It
        can be triggered when a map directive performs regular expression
        matching and a string expression references captures modified by the
        map, or when non-cacheable variables change between the script length
        pass and the script copy pass.

    CVE-2026-56434

        Duplicate finalization of an HTTP subrequest can result in a
        use-after-free. The issue is observable in configurations using
        server-side includes together with proxy_pass and proxy_buffering
        disabled, when an upstream response causes the same subrequest to be
        posted twice.

    CVE-2026-60005

        ngx_http_regex_exec() could replace the captures array without
        clearing r->ncaptures when the new regular expression did not match.
        A subsequent unnamed capture could then access uninitialised memory,
        resulting in memory disclosure.

    For the stable distribution (trixie), these problems have been fixed in
    version 1.26.3-3+deb13u8.

    We recommend that you upgrade your nginx packages.

    For the detailed security status of nginx please refer to
    its security tracker page at:
    https://security-tracker.debian.org/tracker/nginx

    Further information about Debian Security Advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://www.debian.org/security/

    Mailing list: [email protected]

Tenable has extracted the preceding description block directly from the Debian 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://security-tracker.debian.org/tracker/source-package/nginx");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-42533");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-56434");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-60005");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/trixie/nginx");
  script_set_attribute(attribute:"solution", value:
"Upgrade the libnginx-mod-http-geoip packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/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-2026-60005");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-42533");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-42533");

  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:"2026/07/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-http-geoip");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-http-image-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-http-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-http-xslt-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-mail");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-stream");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnginx-mod-stream-geoip");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-extras");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-full");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nginx-light");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  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:"Debian 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_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(13)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 13.0', 'Debian ' + debian_release);
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, 'Debian', cpu);

var pkgs = [
    {'release': '13.0', 'prefix': 'libnginx-mod-http-geoip', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-http-image-filter', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-http-perl', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-http-xslt-filter', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-mail', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-stream', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'libnginx-mod-stream-geoip', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-common', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-core', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-dev', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-doc', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-extras', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-full', 'reference': '1.26.3-3+deb13u8'},
    {'release': '13.0', 'prefix': 'nginx-light', 'reference': '1.26.3-3+deb13u8'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var _release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (_release && prefix && reference) {
    if (deb_check(release:_release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libnginx-mod-http-geoip / libnginx-mod-http-image-filter / etc');
}