EulerOS 2.0 SP12 : krb5 (EulerOS-SA-2026-3271)

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

include('compat.inc');

if (description)
{
  script_id(343741);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/08");

  script_cve_id("CVE-2026-11850");

  script_name(english:"EulerOS 2.0 SP12 : krb5 (EulerOS-SA-2026-3271)");

  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 krb5 packages installed, the EulerOS installation on the remote host is affected by the
following vulnerabilities :

    An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in
    plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2)
    without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then
    truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and
    memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read.
    The attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute
    with bv_len  2, triggering the underflow when the KDC or kadmind reads principal data.(CVE-2026-11850)

Tenable has extracted the preceding description block directly from the EulerOS krb5 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-2026-3271
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9830fd00");
  script_set_attribute(attribute:"solution", value:
"Update the affected krb5 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:M/C:C/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/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-2026-11850");

  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:"2026/06/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5-help");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:krb5-server");
  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_info.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 SP12");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(12)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP12");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP12", "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 = [
  "krb5-1.19.2-6.h19.eulerosv2r12",
  "krb5-client-1.19.2-6.h19.eulerosv2r12",
  "krb5-devel-1.19.2-6.h19.eulerosv2r12",
  "krb5-help-1.19.2-6.h19.eulerosv2r12",
  "krb5-libs-1.19.2-6.h19.eulerosv2r12",
  "krb5-server-1.19.2-6.h19.eulerosv2r12"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"12", 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, "krb5");
}