Siemens RUGGEDCOM RST2428P Improper Input Validation (CVE-2026-23111)

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

include('compat.inc');

if (description)
{
  script_id(505388);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/17");

  script_cve_id("CVE-2026-23111");
  script_xref(name:"ICSA", value:"26-188-05");

  script_name(english:"Siemens RUGGEDCOM RST2428P Improper Input Validation (CVE-2026-23111)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: fix inverted genmask check in
nft_map_catchall_activate()  nft_map_catchall_activate() has an
inverted element activity check compared to its non-catchall
counterpart nft_mapelem_activate() and compared to what is logically
required.  nft_map_catchall_activate() is called from the abort path
to re-activate catchall map elements that were deactivated during a
failed transaction. It should skip elements that are already active
(they don't need re-activation) and process elements that are inactive
(they need to be restored). Instead, the current code does the
opposite: it skips inactive elements and processes active ones.
Compare the non-catchall activate callback, which is correct:
nft_mapelem_activate():     if (nft_set_elem_active(ext,
iter->genmask))         return 0;   /* skip active, process inactive
*/  With the buggy catchall version:    nft_map_catchall_activate():
if (!nft_set_elem_active(ext, genmask))         continue;   /* skip
inactive, process active */  The consequence is that when a DELSET
operation is aborted, nft_setelem_data_activate() is never called for
the catchall element. For NFT_GOTO verdict elements, this means
nft_data_hold() is never called to restore the chain->use reference
count. Each abort cycle permanently decrements chain->use. Once
chain->use reaches zero, DELCHAIN succeeds and frees the chain while
catchall verdict elements still reference it, resulting in a use-
after-free.  This is exploitable for local privilege escalation from
an unprivileged user via user namespaces + nftables on distributions
that enable CONFIG_USER_NS and CONFIG_NF_TABLES.  Fix by removing the
negation so the check matches nft_mapelem_activate(): skip active
elements, process inactive ones.

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/html/ssa-253495.html");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/110002573/");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/ICSA-26-188-05");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-23111");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_cwe_id(20);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/02/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/18");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:ruggedcom_rst2428p_firmware");
  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:ruggedcom_rst2428p_firmware" :
        {"family" : "RuggedCom", "orderNumbers" : ['6GK6242-6PA00'], "versionEndExcluding" : "4.0"}
};

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