Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : attr vulnerability (USN-8691-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8691-1. 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(365389);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/14");

  script_cve_id("CVE-2026-54371");
  script_xref(name:"USN", value:"8691-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : attr vulnerability (USN-8691-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages
installed that are affected by a vulnerability as referenced in the USN-8691-1 advisory.

    It was discovered that attr incorrectly handled symbolic links while traversing directory paths. A local
    attacker who controlled a pathname component could possibly use this issue to redirect privileged attr
    operations to arbitrary files and gain elevated privileges.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue 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-8691-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected attr and / or libattr1 packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N");
  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:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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-2026-54371");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/31");
  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:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:attr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libattr1");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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 || '24.04' >< os_release || '26.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 26.04', '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': 'attr', 'pkgver': '1:2.4.47-1ubuntu1+esm1'},
    {'osver': '14.04', 'pkgname': 'libattr1', 'pkgver': '1:2.4.47-1ubuntu1+esm1'},
    {'osver': '16.04', 'pkgname': 'attr', 'pkgver': '1:2.4.47-2ubuntu0.16.04.1~esm1'},
    {'osver': '16.04', 'pkgname': 'libattr1', 'pkgver': '1:2.4.47-2ubuntu0.16.04.1~esm1'},
    {'osver': '18.04', 'pkgname': 'attr', 'pkgver': '1:2.4.47-2ubuntu0.18.04.1~esm1'},
    {'osver': '18.04', 'pkgname': 'libattr1', 'pkgver': '1:2.4.47-2ubuntu0.18.04.1~esm1'},
    {'osver': '20.04', 'pkgname': 'attr', 'pkgver': '1:2.4.48-5ubuntu0.1~esm1'},
    {'osver': '20.04', 'pkgname': 'libattr1', 'pkgver': '1:2.4.48-5ubuntu0.1~esm1'},
    {'osver': '22.04', 'pkgname': 'attr', 'pkgver': '1:2.5.1-1ubuntu0.1'},
    {'osver': '22.04', 'pkgname': 'libattr1', 'pkgver': '1:2.5.1-1ubuntu0.1'},
    {'osver': '24.04', 'pkgname': 'attr', 'pkgver': '1:2.5.2-1ubuntu0.1'},
    {'osver': '24.04', 'pkgname': 'libattr1', 'pkgver': '1:2.5.2-1ubuntu0.1'},
    {'osver': '26.04', 'pkgname': 'attr', 'pkgver': '1:2.5.2-4ubuntu0.1'},
    {'osver': '26.04', 'pkgname': 'libattr1', 'pkgver': '1:2.5.2-4ubuntu0.1'}
];

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, 'attr / libattr1');
}