F5 Networks BIG-IP : libssh vulnerability (K05295501)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from F5 Networks BIG-IP Solution K05295501.
#
# @NOAGENT@
##

include('compat.inc');

if (description)
{
  script_id(184231);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/07");

  script_cve_id("CVE-2020-1730");

  script_name(english:"F5 Networks BIG-IP : libssh vulnerability (K05295501)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The version of F5 Networks BIG-IP installed on the remote host is prior to tested version. It is, therefore, affected by
a vulnerability as referenced in the K05295501 advisory.

  - A flaw was found in libssh versions before 0.8.9 and before 0.9.4 in the way it handled AES-CTR (or DES
    ciphers if enabled) ciphers. The server or client could crash when the connection hasn't been fully
    initialized and the system tries to cleanup the ciphers when closing the connection. The biggest threat
    from this vulnerability is system availability. (CVE-2020-1730)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://my.f5.com/manage/s/article/K05295501");
  script_set_attribute(attribute:"solution", value:
"The vendor has acknowledged the vulnerability, but no solution has been provided.
Refer to the vendor for remediation guidance.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  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:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-1730");

  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:"2020/04/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/11/02");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_advanced_firewall_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:f5:big-ip");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"F5 Networks Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("f5_bigip_detect.nbin");
  script_require_keys("Host/local_checks_enabled", "Host/BIG-IP/hotfix", "Host/BIG-IP/modules", "Host/BIG-IP/version");

  exit(0);
}


include('f5_func.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var version = get_kb_item('Host/BIG-IP/version');
if ( ! version ) audit(AUDIT_OS_NOT, 'F5 Networks BIG-IP');
if ( isnull(get_kb_item('Host/BIG-IP/hotfix')) ) audit(AUDIT_KB_MISSING, 'Host/BIG-IP/hotfix');
if ( ! get_kb_item('Host/BIG-IP/modules') ) audit(AUDIT_KB_MISSING, 'Host/BIG-IP/modules');

var sol = 'K05295501';
var vmatrix = {
  'AFM': {
    'affected': [
      '16.0.0','15.0.0-15.1.0','14.1.0-14.1.2','13.1.0-13.1.3','12.1.0-12.1.5'
    ],
  }
};

if (bigip_is_affected(vmatrix:vmatrix, sol:sol))
{
  var extra = NULL;
  if (report_verbosity > 0) extra = bigip_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : extra
  );
}
else
{
  var tested = bigip_get_tested_modules();
  var audit_extra = 'For BIG-IP module(s) ' + tested + ',';
  if (tested) audit(AUDIT_INST_VER_NOT_VULN, audit_extra, version);
  else audit(AUDIT_HOST_NOT, 'running the affected module AFM');
}