Siemens SENTRON PAC Out-of-bounds Write (CVE-2020-17437)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(505360);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/09");

  script_cve_id("CVE-2020-17437");
  script_xref(name:"ICSA", value:"20-343-01");
  script_xref(name:"CEA-ID", value:"CEA-2020-0139");

  script_name(english:"Siemens SENTRON PAC Out-of-bounds Write (CVE-2020-17437)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"The TCP/IP stack (uIP) in affected devices is vulnerable to out-of-bounds write when 
processing TCP packets with urgent pointer (URG) where the location of the TCP 
data payload is calculated improperly. An attacker located in the same network could trigger 
a Denial-of-Service condition on the device by sending a specially crafted IP packet.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/pdf/ssa-541018.pdf");
  script_set_attribute(attribute:"see_also", value:"https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01");
  script_set_attribute(attribute:"see_also", value:"https://www.kb.cert.org/vuls/id/815128");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/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:L/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-2020-17437");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(787);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/12/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/12/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/03");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:sentron_pac2200_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:sentron_pac3200_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:sentron_pac3200t_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:sentron_pac3220_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:sentron_pac4200_firmware");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tenable.ot");

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

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/Siemens");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Siemens');

var asset = tenable_ot::assets::get(vendor:'Siemens');

var vuln_cpes = {
    "cpe:/o:siemens:sentron_pac2200_firmware" :
        {"versionEndExcluding" : "3.2.2", "family" : "SiemensSENTRON"},
    "cpe:/o:siemens:sentron_pac3200_firmware" :
        {"versionEndExcluding" : "2.4.7", "family" : "SiemensSENTRON"},
    "cpe:/o:siemens:sentron_pac3200t_firmware" :
        {"versionEndExcluding" : "3.2.2", "family" : "SiemensSENTRON"},
    "cpe:/o:siemens:sentron_pac3220_firmware" :
        {"versionEndExcluding" : "3.2.0", "family" : "SiemensSENTRON"},
    "cpe:/o:siemens:sentron_pac4200_firmware" :
        {"versionEndExcluding" : "2.3.0", "family" : "SiemensSENTRON"}
};

tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_WARNING);