Juniper Junos BGP Update DoS (JSA11033)

#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(138604);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");

  script_cve_id("CVE-2020-1646");
  script_xref(name:"JSA", value:"JSA11033");
  script_xref(name:"IAVA", value:"2020-A-0320-S");

  script_name(english:"Juniper Junos BGP Update DoS (JSA11033)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"According to the self-reported version of Junos OS on the remote device, it is affected by a denial of service (DoS)
vulnerability due to how it processes a specific UPDATE for an EBGP peer. An unauthenticated, remote attacker can
exploit this, by sending a crafted UPDATE, in order to crash the routing process daemon (RPD) and cause a restart.

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/JSA11033");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper advisory JSA11033");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-1646");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/07/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/17");

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

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

  script_copyright(english:"This script is Copyright (C) 2020-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('junos.inc');

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

if (ver != '17.3R3-S6' && ver != '17.4R2-S7' && ver != '18.1R3-S7')
  audit(AUDIT_INST_VER_NOT_VULN, 'Junos', ver);

fixes = make_array();
fixes['17.3'] = '17.3R3-S7';
fixes['17.4'] = '17.4R2-S8';
fixes['18.1'] = '18.1R3-S8';

fix = check_junos(ver:ver, fixes:fixes, exit_on_fail:TRUE);
report = get_report(ver:ver, fix:fix);
security_report_v4(severity:SECURITY_WARNING, port:0, extra:report);