NewStart CGSL MAIN 7.02 : libssh2 Multiple Vulnerabilities (NS-SA-2026-0094)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2026-0094. The text
# itself is copyright (C) ZTE, Inc.
##

include('compat.inc');

if (description)
{
  script_id(343596);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/08");

  script_cve_id(
    "CVE-2025-15661",
    "CVE-2026-7598",
    "CVE-2026-55199",
    "CVE-2026-58051"
  );

  script_name(english:"NewStart CGSL MAIN 7.02 : libssh2 Multiple Vulnerabilities (NS-SA-2026-0094)");

  script_set_attribute(attribute:"synopsis", value:
"The remote NewStart CGSL host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote NewStart CGSL host, running version MAIN 7.02, has libssh2 packages installed that are affected by multiple
vulnerabilities:

  - A security vulnerability has been detected in libssh2 up to 1.11.1. The impacted element is the function
    userauth_password of the file src/userauth.c. Such manipulation of the argument username_len/password_len
    leads to integer overflow. The attack may be launched remotely. The name of the patch is
    256d04b60d80bf1190e96b0ad1e91b2174d744b1. A patch should be applied to remediate this issue.
    (CVE-2026-7598)

  - libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the
    sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to
    disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can
    supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and
    REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the
    missing validation of available packet buffer size before the memcpy operation. (CVE-2025-15661)

  - libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service
    vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause
    a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set
    nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over
    60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not
    apply to CPU-bound loops. (CVE-2026-55199)

  - libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries
    before parsing populates them, so a parse failure reaching the cleanup path leaves
    libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the
    publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-
    influenceable attrs pointer in a connecting libssh2 client. (CVE-2026-58051)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://security.gd-linux.com/notice/NS-SA-2026-0094");
  script_set_attribute(attribute:"see_also", value:"https://security.gd-linux.com/info/CVE-2025-15661");
  script_set_attribute(attribute:"see_also", value:"https://security.gd-linux.com/info/CVE-2026-55199");
  script_set_attribute(attribute:"see_also", value:"https://security.gd-linux.com/info/CVE-2026-58051");
  script_set_attribute(attribute:"see_also", value:"https://security.gd-linux.com/info/CVE-2026-7598");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL libssh2 packages. Note that updated packages may not be available yet. Please contact ZTE
for more information.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-7598");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2025-15661");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-58051");

  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:"2026/05/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/07");
  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:zte:cgsl_main:libssh2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libssh2-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libssh2-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:libssh2-docs");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:zte:cgsl_main:7");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"NewStart CGSL 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/ZTE-CGSL/release", "Host/ZTE-CGSL/rpm-list", "Host/cpu");

  exit(0);
}

include('rpm2.inc');

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

var os_release = get_kb_item('Host/ZTE-CGSL/release');
if (isnull(os_release) || os_release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, 'NewStart Carrier Grade Server Linux');

if (os_release !~ "CGSL\sMAIN\s7\.02")
  audit(AUDIT_OS_NOT, 'NewStart CGSL MAIN 7.02');

if (!get_kb_item('Host/ZTE-CGSL/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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'NewStart Carrier Grade Server Linux', cpu);

var flag = 0;

var pkgs = {
  'CGSL MAIN 7.02': [
    'libssh2-1.11.0-1.zncgsl7.11',
    'libssh2-core-1.11.0-1.zncgsl7.11',
    'libssh2-devel-1.11.0-1.zncgsl7.11',
    'libssh2-docs-1.11.0-1.zncgsl7.11'
  ]
};
var pkg_list = pkgs[os_release];
var pkg;
foreach (pkg in pkg_list)
  if (rpm_check(reference:pkg, release:'ZTE ' + os_release, rpm_spec_vers_cmp:TRUE)) 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, 'libssh2');
}