EulerOS Virtualization 2.11.1 : libxml2 (EulerOS-SA-2026-3437)

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

include('compat.inc');

if (description)
{
  script_id(347208);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/18");

  script_cve_id(
    "CVE-2024-56171",
    "CVE-2025-6021",
    "CVE-2025-6170",
    "CVE-2025-24928",
    "CVE-2025-27113",
    "CVE-2025-32414",
    "CVE-2025-32415",
    "CVE-2025-49794",
    "CVE-2025-49796",
    "CVE-2026-0989",
    "CVE-2026-0990",
    "CVE-2026-0992",
    "CVE-2026-1757"
  );
  script_xref(name:"IAVA", value:"2025-A-0123-S");
  script_xref(name:"IAVA", value:"2025-A-0840-S");

  script_name(english:"EulerOS Virtualization 2.11.1 : libxml2 (EulerOS-SA-2026-3437)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the libxml2 packages installed, the EulerOS Virtualization installation on the remote host
is affected by the following vulnerabilities :

    libxml2 before 2.12.10 and 2.13.x before 2.13.6 has a NULL pointer dereference in xmlPatMatch in
    pattern.c.(CVE-2025-27113)

    libxml2 before 2.12.10 and 2.13.x before 2.13.6 has a use-after-free in xmlSchemaIDCFillNodeTables and
    xmlSchemaBubbleIDCNodeTables in xmlschemas.c. To exploit this, a crafted XML document must be validated
    against an XML schema with certain identity constraints, or a crafted XML schema must be
    used.(CVE-2024-56171)

    libxml2 before 2.12.10 and 2.13.x before 2.13.6 has a stack-based buffer overflow in xmlSnprintfElements
    in valid.c. To exploit this, DTD validation must occur for an untrusted document or untrusted DTD. NOTE:
    this is similar to CVE-2017-9047.(CVE-2025-24928)

    In libxml2 before 2.13.8 and 2.14.x before 2.14.2, xmlSchemaIDCFillNodeTables in xmlschemas.c has a heap-
    based buffer under-read. To exploit this, a crafted XML document must be validated against an XML schema
    with certain identity constraints, or a crafted XML schema must be used.(CVE-2025-32415)

    In libxml2 before 2.13.8 and 2.14.x before 2.14.2, out-of-bounds memory access can occur in the Python API
    (Python bindings) because of an incorrect return value. This occurs in xmlPythonFileRead and
    xmlPythonFileReadRaw because of a difference between bytes and characters.(CVE-2025-32414)

    A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations
    can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of
    service when processing crafted input.(CVE-2025-6021)

    A flaw was found in the interactive shell of the xmllint command-line tool, used for parsing XML files.
    When a user inputs an overly long command, the program does not check the input size properly, which can
    cause it to crash. This issue might allow attackers to run harmful code in rare configurations without
    modern protections.(CVE-2025-6170)

    A vulnerability was found in libxml2. Processing certain sch:name elements from the input XML file can
    trigger a memory corruption issue. This flaw allows an attacker to craft a malicious XML input file that
    can lead libxml to crash, resulting in a denial of service or other possible undefined behavior due to
    sensitive data being corrupted in memory.(CVE-2025-49796)

    A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under
    certain circumstances when the XML schematron has the sch:name path='...'/ schema elements. This
    flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the
    program's crash using libxml or other possible undefined behaviors.(CVE-2025-49794)

    A flaw was identified in the interactive shell of the xmllint utility, part of the libxml2 project, where
    memory allocated for user input is not properly released under certain conditions. When a user submits
    input consisting only of whitespace, the program skips command execution but fails to free the allocated
    buffer. Repeating this action causes memory to continuously accumulate. Over time, this can exhaust system
    memory and terminate the xmllint process, creating a denial-of-service condition on the local
    system.(CVE-2026-1757)

    A flaw was found in the libxml2 library. This uncontrolled resource consumption vulnerability occurs when
    processing XML catalogs that contain repeated nextCatalog elements pointing to the same downstream
    catalog. A remote attacker can exploit this by supplying crafted catalogs, causing the parser to
    redundantly traverse catalog chains. This leads to excessive CPU consumption and degrades application
    availability, resulting in a denial-of-service condition.(CVE-2026-0992)

    A flaw was identified in the RelaxNG parser of libxml2 related to how external schema inclusions are
    handled. The parser does not enforce a limit on inclusion depth when resolving nested include
    directives. Specially crafted or overly complex schemas can cause excessive recursion during parsing. This
    may lead to stack exhaustion and application crashes, creating a denial-of-service risk.(CVE-2026-0989)

    A flaw was found in libxml2, an XML parsing library. This uncontrolled recursion vulnerability occurs in
    the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references
    itself. A remote attacker could exploit this configuration-dependent issue by providing a specially
    crafted XML catalog, leading to infinite recursion and call stack exhaustion. This ultimately results in a
    segmentation fault, causing a Denial of Service (DoS) by crashing affected applications.(CVE-2026-0990)

Tenable has extracted the preceding description block directly from the EulerOS Virtualization libxml2 security
advisory.

Note that Nessus has not tested for these issues 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-2026-3437
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4edc8690");
  script_set_attribute(attribute:"solution", value:
"Update the affected libxml2 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/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-2024-56171");

  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:"2025/02/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libxml2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:python3-libxml2");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:2.11.1");
  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:"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/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 (uvp != "2.11.1") audit(AUDIT_OS_NOT, "EulerOS Virtualization 2.11.1");
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 ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

var flag = 0;

var pkgs = [
  "libxml2-2.9.12-5.h41.eulerosv2r11",
  "python3-libxml2-2.9.12-5.h41.eulerosv2r11"
];

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

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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, "libxml2");
}