EulerOS 2.0 SP13 : kbd (EulerOS-SA-2026-4056)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(364887);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/12");

  script_cve_id("CVE-2026-72693");

  script_name(english:"EulerOS 2.0 SP13 : kbd (EulerOS-SA-2026-4056)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the kbd packages installed, the EulerOS installation on the remote host is affected by the
following vulnerabilities :

    `openvt -u` is intended to identify the owner of the current VT and then execute `login` as that user from
    a privileged context. In the documented `kbrequest`/init usage, the ownership test in
    `authenticate_user()` relies on `stat('/proc/pid/fd/0')`. `stat()` on `/proc/pid/fd/0` follows
    the symlink to the underlying TTY device node. As a result, `buf.st_uid` reflects the owner of the TTY
    node rather than the owner of the process holding the file descriptor. If the TTY owner returns to `root`
    or the getty owner after logout while an unprivileged process still has `fd 0` attached to that TTY, the
    check can incorrectly treat that process as belonging to the privileged console owner. Once that check
    succeeds, the `-u` path executes a passwordless login as the selected user. In the documented
    `kbrequest`/init deployment using `openvt -us`, this can result in passwordless `login -f root` on the
    spawned VT. This report establishes that privilege escalation path for that documented deployment; it does
    not claim equivalent reachability for deployments that do not use `openvt -u` from a privileged
    `kbrequest`/init path.(CVE-2026-72693)

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

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2026-4056
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?583bed2d");
  script_set_attribute(attribute:"solution", value:
"Update the affected kbd packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-72693");

  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:"2026/08/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:kbd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:kbd-help");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:kbd-legacy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:kbd-misc");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei 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/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

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

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (_release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(13)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/rpm-list")) 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$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "kbd-2.5.1-1.h4.eulerosv2r13",
  "kbd-help-2.5.1-1.h4.eulerosv2r13",
  "kbd-legacy-2.5.1-1.h4.eulerosv2r13",
  "kbd-misc-2.5.1-1.h4.eulerosv2r13"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"13", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    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, "kbd");
}