Siemens SIMATIC S7-1500 Use After Free (CVE-2025-38471)

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

include('compat.inc');

if (description)
{
  script_id(505233);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/24");

  script_cve_id("CVE-2025-38471");

  script_name(english:"Siemens SIMATIC S7-1500 Use After Free (CVE-2025-38471)");

  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:
tls: always refresh the queue when reading sock    After recent
changes in net-next TCP compacts skbs much more  aggressively. This
unearthed a bug in TLS where we may try  to operate on an old skb when
checking if all skbs in the  queue have matching decrypt state and
geometry.        BUG: KASAN: slab-use-after-free in
tls_strp_check_rcv+0x898/0x9a0 [tls]      (net/tls/tls_strp.c:436
net/tls/tls_strp.c:530 net/tls/tls_strp.c:544)      Read of size 4 at
addr ffff888013085750 by task tls/13529        CPU: 2 UID: 0 PID:
13529 Comm: tls Not tainted 6.16.0-rc5-virtme      Call Trace:
kasan_report+0xca/0x100       tls_strp_check_rcv+0x898/0x9a0 [tls]
tls_rx_rec_wait+0x2c9/0x8d0 [tls]       tls_sw_recvmsg+0x40f/0x1aa0
[tls]       inet_recvmsg+0x1c3/0x1f0    Always reload the queue, fast
path is to have the record in the queue  when we wake, anyway (IOW the
path going down if !strp->stm.full_len).

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-082556.html");
  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:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-38471");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(416);

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/06/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/06/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/03/23");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1500_cpu_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:simatic_s7-1500_cpu_firmware:3.1.5" :
        {"versionStartIncluding" : "3.1.5", "family" : "S71500", "orderNumbers" : ['6ES7518-4AX00-1AB0', '6ES7518-4AX00-1AC0', '6ES7518-4FX00-1AB0', '6ES7518-4FX00-1AC0']},
    "cpe:/o:siemens:siplus_s7-1500_cpu_firmware" :
        {"family" : "S71500", "orderNumbers" : ['6AG1518-4AX00-4AC0']}
};

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