Debian dla-4650 : giflib-tools - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-4650. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(322947);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/02");

  script_cve_id("CVE-2026-23868", "CVE-2026-26740");

  script_name(english:"Debian dla-4650 : giflib-tools - 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 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-4650 advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4650-1                [email protected]
    https://www.debian.org/lts/security/                         Tobias Frost
    June 26, 2026                                 https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : giflib
    Version        : 5.1.9-2+deb11u1 $bookworm_VERSION
    CVE ID         : CVE-2026-23868 CVE-2026-26740
    Debian Bug     : 1130495 1131368

    Two vulnerabilties have been found in giflib, a package of portable
    tools and library routines for working with GIF images, potentially
    allowing Denial of Service.

    CVE-2026-23868

      Giflib contains a double-free vulnerability that is the result of a
      shallow copy in GifMakeSavedImage and incorrect error handling. The
      conditions needed to trigger this vulnerability are difficult but may
      be possible.

    CVE-2026-26740

      A Buffer Overflow vulnerability in giflib v.5.2.2 allows a remote
      attacker to cause a denial of service via the EGifGCBToExtension
      overwriting an existing Graphic Control Extension block without
      validating its allocated size.

    For Debian 11 bullseye, these problems have been fixed in version
    5.1.9-2+deb11u1.

    We recommend that you upgrade your giflib packages.

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

    Further information about Debian LTS security advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://wiki.debian.org/LTS
    Attachment:
    signature.asc
    Description: PGP signature

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/giflib");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-23868");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-26740");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/giflib");
  script_set_attribute(attribute:"solution", value:
"Upgrade the giflib-tools packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:N/UI:R/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:"cvss_score_source", value:"CVE-2026-26740");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-23868");

  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:"2026/03/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:giflib-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgif-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgif7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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:"^(11)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 11.0', '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': '11.0', 'prefix': 'giflib-tools', 'reference': '5.1.9-2+deb11u1'},
    {'release': '11.0', 'prefix': 'libgif-dev', 'reference': '5.1.9-2+deb11u1'},
    {'release': '11.0', 'prefix': 'libgif7', 'reference': '5.1.9-2+deb11u1'}
];

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, 'giflib-tools / libgif-dev / libgif7');
}