EulerOS 2.0 SP11 : libssh (EulerOS-SA-2026-2252)

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

include('compat.inc');

if (description)
{
  script_id(319946);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/10");

  script_cve_id(
    "CVE-2026-0964",
    "CVE-2026-0965",
    "CVE-2026-0966",
    "CVE-2026-0967",
    "CVE-2026-0968",
    "CVE-2026-3731"
  );
  script_xref(name:"IAVA", value:"2026-A-0166");

  script_name(english:"EulerOS 2.0 SP11 : libssh (EulerOS-SA-2026-2252)");

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

    The API function `ssh_get_hexa()` is vulnerable, when 0-lenght
    input is provided to this function. This function is used internally
    in `ssh_get_fingerprint_hash()` and `ssh_print_hexa()` (deprecated),
    which is vulnerable to the same input (length is provided by the
    calling application).

    The function is also used internally in the gssapi code for logging
    the OIDs received by the server during GSSAPI authentication. This
    could be triggered remotely, when the server allows GSSAPI authentication
    and logging verbosity is set at least to SSH_LOG_PACKET (3). This
    could cause self-DoS of the per-connection daemon process.(CVE-2026-0966)

    A flaw was found in libssh in which a malicious SFTP (SSH File Transfer Protocol) server can exploit this
    by sending a malformed 'longname' field within an `SSH_FXP_NAME` message during a file listing operation.
    This missing null check can lead to reading beyond allocated memory on the heap. This can cause unexpected
    behavior or lead to a denial of service (DoS) due to application crashes.(CVE-2026-0968)

    A flaw was found in libssh where it can attempt to open arbitrary files during configuration parsing. A
    local attacker can exploit this by providing a malicious configuration file or when the system is
    misconfigured. This vulnerability could lead to a Denial of Service (DoS) by causing the system to try and
    access dangerous files, such as block devices or large system files, which can disrupt normal
    operations.(CVE-2026-0965)

    A malicious SCP server can send unexpected paths that could make the
    client application override local files outside of working directory.
    This could be misused to create malicious executable or configuration
    files and make the user execute them under specific consequences.

    This is the same issue as in OpenSSH, tracked as CVE-2019-6111.(CVE-2026-0964)

    A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts
    files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to
    inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in
    a Denial of Service (DoS) for the client.(CVE-2026-0967)

    A weakness has been identified in libssh up to 0.11.3. The impacted element is the function
    sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension
    Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may
    be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This
    patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected
    component.(CVE-2026-3731)

Tenable has extracted the preceding description block directly from the EulerOS libssh 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-2026-2252
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0ddabad1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libssh packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/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:L/PR:N/UI:N/S:U/C:N/I:L/A:H");
  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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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-2026-0966");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-3731");

  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:"2026/02/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libssh-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:libssh-help");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"II");
  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 SP11");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(11)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP11", "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 ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

var flag = 0;

var pkgs = [
  "libssh-0.9.6-2.h20.eulerosv2r11",
  "libssh-devel-0.9.6-2.h20.eulerosv2r11",
  "libssh-help-0.9.6-2.h20.eulerosv2r11"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"11", 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, "libssh");
}