Siemens RUGGEDCOM RST2428P Permissive Regular Expression (CVE-2025-40271)

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

include('compat.inc');

if (description)
{
  script_id(505403);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/20");

  script_cve_id("CVE-2025-40271");

  script_name(english:"Siemens RUGGEDCOM RST2428P Permissive Regular Expression (CVE-2025-40271)");

  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:
fs/proc: fix uaf in proc_readdir_de()  Pde is erased from subdir
rbtree through rb_erase(), but not set the node to EMPTY, which may
result in uaf access.  We should use RB_CLEAR_NODE() set the erased
node to EMPTY, then pde_subdir_next() will return NULL to avoid uaf
access.  We found an uaf issue while using stress-ng testing, need to
run testcase getdent and tun in the same time.  The steps of the issue
is as follows:  1) use getdent to traverse dir
/proc/pid/net/dev_snmp6/, and current    pde is tun3;  2) in the [time
windows] unregister netdevice tun3 and tun2, and erase    them from
rbtree.  erase tun3 first, and then erase tun2.  the    pde(tun2) will
be released to slab;  3) continue to getdent process, then
pde_subdir_next() will return    pde(tun2) which is released, it will
case uaf access.  CPU 0                                      |    CPU
1 --------------------------------------------------------------------
----- traverse dir /proc/pid/net/dev_snmp6/      |
unregister_netdevice(tun->dev)   //tun3 tun2 sys_getdents64()
|   iterate_dir()                            |     proc_readdir()
|       proc_readdir_de()                    |
snmp6_unregister_dev()         pde_get(de);                       |
proc_remove()         read_unlock(&proc_subdir_lock);    |
remove_proc_subtree()                                            |
write_lock(&proc_subdir_lock);         [time window]
|           rb_erase(&root->subdir_node, &parent->subdir);
|           write_unlock(&proc_subdir_lock);
read_lock(&proc_subdir_lock);      |         next =
pde_subdir_next(de);        |         pde_put(de);
|         de = next;    //UAF                |  rbtree of dev_snmp6
|                     pde(tun3)                      /    \
NULL  pde(tun2)

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:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/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-2025-40271");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_cwe_id(625);

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/12/06");
  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_HOLE);