F5 Networks BIG-IP : OpenSSH client vulnerability (K48050136)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from F5 Networks BIG-IP Solution K48050136.
#
# @NOAGENT@
##

include('compat.inc');

if (description)
{
  script_id(166567);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/21");

  script_cve_id("CVE-2020-14145");

  script_name(english:"F5 Networks BIG-IP : OpenSSH client vulnerability (K48050136)");

  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 15.1.9 / 16.1.4 / 17.1.0. It is, therefore,
affected by a vulnerability as referenced in the K48050136 advisory.

    The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in
    the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts
    (where no host key for the server has been cached by the client). NOTE: some reports state that 8.5 and
    8.6 are also affected.(CVE-2020-14145)ImpactSSH sessions may be vulnerable to a man-in-the-middle attack.

Tenable has extracted the preceding description block directly from the F5 Networks BIG-IP security advisory.

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/K48050136");
  script_set_attribute(attribute:"solution", value:
"Upgrade to one of the non-vulnerable versions listed in the F5 Solution K48050136.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
  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:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-14145");

  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:"2020/06/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/10/26");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_access_policy_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_advanced_firewall_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_acceleration_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_security_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_visibility_and_reporting");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_domain_name_system");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_global_traffic_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_link_controller");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_local_traffic_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_policy_enforcement_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) 2022-2025 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", "Settings/ParanoidReport");

  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');

if (report_paranoia < 2) audit(AUDIT_PARANOID);

var sol = 'K48050136';
var vmatrix = {
  'AFM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'AM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'APM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'ASM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'AVR': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'DNS': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'GTM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'LC': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'LTM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  },
  'PEM': {
    'affected': [
      '17.0.0','16.0.0-16.1.3','15.1.0-15.1.8','14.1.0-14.1.5','13.1.0-13.1.5'
    ],
    'unaffected': [
      '17.1.0','16.1.4','15.1.9'
    ],
  }
};

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 any of the affected modules');
}