Juniper Junos OS Authentication for Critical Function (CVE-2024-21620)

#TRUSTED 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
#TRUST-RSA-SHA256 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
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(215002);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/22");

  script_cve_id("CVE-2024-21620");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2023/11/17");
  script_xref(name:"JSA", value:"JSA76390");

  script_name(english:"Juniper Junos OS Authentication for Critical Function (CVE-2024-21620)");

  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 Junos OS installed on the remote host is affected by a vulnerability as referenced in the
JSA76390 advisory.

  - An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in 
    J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an attacker to construct a URL that 
    when visited by another user enables the attacker to execute commands with the target's permissions, 
    including an administrator. A specific invocation of the emit_debug_note method in webauth_operation.php 
    will echo back the data it receives. (CVE-2024-21620)

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://kb.juniper.net/JSA76390");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper advisory JSA76390");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/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:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"manual");
  script_set_attribute(attribute:"cvss_score_rationale", value:"Set to score from vendor advisory.");

  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:"2024/01/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/01/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/02/05");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:juniper:junos");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("junos_version.nasl");
  script_require_keys("Host/Juniper/JUNOS/Version", "Host/Juniper/model");

  exit(0);
}

include('junos.inc');
include('junos_kb_cmd_func.inc');

var ver = get_kb_item_or_exit('Host/Juniper/JUNOS/Version');
var model = get_kb_item_or_exit('Host/Juniper/model');

if (model !~ "^(EX|SRX)")
  audit(AUDIT_DEVICE_NOT_VULN, model);

var vuln_ranges = [
  {'min_ver':'0.0', 'fixed_ver':'20.4R3-S10', 'model':'^(EX|SRX)'},
  {'min_ver':'21.2', 'fixed_ver':'21.2R3-S8', 'model':'^(EX|SRX)'},
  {'min_ver':'21.4', 'fixed_ver':'21.4R3-S6', 'model':'^(EX|SRX)'},
  {'min_ver':'22.1', 'fixed_ver':'22.1R3-S5', 'model':'^(EX|SRX)'},
  {'min_ver':'22.2', 'fixed_ver':'22.2R3-S3', 'model':'^(EX|SRX)'},
  {'min_ver':'22.3', 'fixed_ver':'22.3R3-S2', 'model':'^(EX|SRX)'},
  {'min_ver':'22.4', 'fixed_ver':'22.4R3-S1', 'model':'^(EX|SRX)'},
  {'min_ver':'23.2', 'fixed_ver':'23.2R2', 'model':'^(EX|SRX)'},
  {'min_ver':'23.4', 'fixed_ver':'23.4R2', 'model':'^(EX|SRX)'},
];

var override = TRUE;
var buf = junos_command_kb_item(cmd:"show configuration | display set");
if (!empty_or_null(buf))
{
  override = FALSE;
  if(!junos_check_config(buf:buf, pattern:"^set system services web-management http(s)?")) 
    audit(AUDIT_HOST_NOT, 'vulnerable as J-Web is not enabled');
}

var fix = junos_compare_range(target_version:ver, vuln_ranges:vuln_ranges);
if (empty_or_null(fix))
  audit(AUDIT_INST_VER_NOT_VULN, 'Junos OS', ver);
junos_report(ver:ver, fix:fix, override:override, severity:SECURITY_WARNING);