EulerOS 2.0 SP13 : libssh (EulerOS-SA-2026-4064)

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

include('compat.inc');

if (description)
{
  script_id(364825);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/12");

  script_cve_id(
    "CVE-2026-59843",
    "CVE-2026-59844",
    "CVE-2026-59845",
    "CVE-2026-59847",
    "CVE-2026-59850"
  );
  script_xref(name:"IAVA", value:"2026-A-0788");

  script_name(english:"EulerOS 2.0 SP13 : libssh (EulerOS-SA-2026-4064)");

  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 :

    A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in
    SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial
    of service.(CVE-2026-59843)

    A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as
    process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree,
    leading to local denial of service.(CVE-2026-59845)

    A flaw was found in libssh. A remote authenticated client can issue SSH_FXP_READ requests with an
    arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially
    exhaust it through repeated requests.(CVE-2026-59844)

    A flaw was found in libssh. If data packets are processed after a channel is closed, channel data
    callbacks can be invoked after the associated data has already been freed, leading to crashes or possible
    use-after-free conditions.(CVE-2026-59850)

    A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can
    effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire
    without detection.(CVE-2026-59847)

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-2026-4064
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?14ab5ac5");
  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:C/A:N");
  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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-59847");

  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:"2026/07/21");
  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: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:"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_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 = [
  "libssh-0.9.6-7.h11.eulerosv2r13",
  "libssh-devel-0.9.6-7.h11.eulerosv2r13",
  "libssh-help-0.9.6-7.h11.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_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");
}