Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS : libpng vulnerabilities (USN-8639-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8639-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(365417);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/13");

  script_cve_id(
    "CVE-2018-14048",
    "CVE-2026-33416",
    "CVE-2026-33636",
    "CVE-2026-34757",
    "CVE-2026-40930"
  );
  script_xref(name:"IAVA", value:"2026-A-0272-S");
  script_xref(name:"IAVA", value:"2026-A-0322-S");
  script_xref(name:"IAVA", value:"2026-A-0559");
  script_xref(name:"USN", value:"8639-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS : libpng vulnerabilities (USN-8639-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS host has packages installed that are
affected by multiple vulnerabilities as referenced in the USN-8639-1 advisory.

    Patrick Keshishian discovered that libpng incorrectly handled certain text chunks. An attacker could
    possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS.
    (CVE-2016-10087)

    It was discovered that libpng incorrectly handled certain malformed images. An attacker could possibly use
    this issue to cause a denial of service. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-14048)

    It was discovered that libpng incorrectly handled memory when freeing certain images. An attacker could
    possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS.
    (CVE-2019-7317)

    It was discovered that libpng incorrectly handled memory when processing certain images. An attacker could
    possibly use this issue to cause a denial of service, or execute arbitrary code. This issue only affected
    Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-33416)

    It was discovered that libpng incorrectly handled certain images. An attacker could possibly use this
    issue to cause a denial of service or execute arbitrary code. This issue only affected Ubuntu 20.04 LTS.
    (CVE-2026-33636)

    It was discovered that libpng incorrectly handled memory when processing certain images. An attacker could
    possibly use this issue to cause a denial of service or obtain sensitive information. This issue only
    affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-34757)

    Seung Min Shin discovered that libpng incorrectly handled certain animated images. An attacker could
    possibly use this issue to cause libpng to misinterpret image data. This issue only affected Ubuntu 20.04
    LTS and Ubuntu 22.04 LTS. (CVE-2026-40930)

Tenable has extracted the preceding description block directly from the Ubuntu 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://ubuntu.com/security/notices/USN-8639-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/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-2018-14048");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-34757");

  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:"2018/07/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpng-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpng12-0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpng16-16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpng3");
  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:"Ubuntu Local Security Checks");

  script_copyright(english:"Ubuntu Security Notice (C) 2026 Canonical, Inc. / NASL script (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/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);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('14.04' >< os_release || '16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04 / 20.04 / 22.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '14.04', 'pkgname': 'libpng12-0', 'pkgver': '1.2.50-1ubuntu2.14.04.3+esm2', 'cves': ['CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '14.04', 'pkgname': 'libpng3', 'pkgver': '1.2.50-1ubuntu2.14.04.3+esm2', 'cves': ['CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '16.04', 'pkgname': 'libpng12-0', 'pkgver': '1.2.54-1ubuntu1.1+esm3', 'cves': ['CVE-2016-10087', 'CVE-2019-7317', 'CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '16.04', 'pkgname': 'libpng3', 'pkgver': '1.2.54-1ubuntu1.1+esm3', 'cves': ['CVE-2016-10087', 'CVE-2019-7317', 'CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '18.04', 'pkgname': 'libpng-tools', 'pkgver': '1.6.34-1ubuntu0.18.04.2+esm3', 'cves': ['CVE-2018-14048', 'CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '18.04', 'pkgname': 'libpng16-16', 'pkgver': '1.6.34-1ubuntu0.18.04.2+esm3', 'cves': ['CVE-2018-14048', 'CVE-2026-33416', 'CVE-2026-34757']},
    {'osver': '20.04', 'pkgname': 'libpng-tools', 'pkgver': '1.6.37-2ubuntu0.1~esm3', 'cves': ['CVE-2026-33416', 'CVE-2026-33636', 'CVE-2026-34757', 'CVE-2026-40930']},
    {'osver': '20.04', 'pkgname': 'libpng16-16', 'pkgver': '1.6.37-2ubuntu0.1~esm3', 'cves': ['CVE-2026-33416', 'CVE-2026-33636', 'CVE-2026-34757', 'CVE-2026-40930']},
    {'osver': '22.04', 'pkgname': 'libpng-tools', 'pkgver': '1.6.37-3ubuntu0.6', 'cves': ['CVE-2026-40930']},
    {'osver': '22.04', 'pkgname': 'libpng16-16', 'pkgver': '1.6.37-3ubuntu0.6', 'cves': ['CVE-2026-40930']}
];

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

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libpng-tools / libpng12-0 / libpng16-16 / libpng3');
}