Siemens SIMATIC S7-1500 CPU 1518 MFP Improper Input Validation (CVE-2025-39782)

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

include('compat.inc');

if (description)
{
  script_id(505837);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/28");

  script_cve_id("CVE-2025-39782");

  script_name(english:"Siemens SIMATIC S7-1500 CPU 1518 MFP Improper Input Validation (CVE-2025-39782)");

  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:
jbd2: prevent softlockup in jbd2_log_do_checkpoint()    Both
jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()
periodically release j_list_lock after processing a batch of buffers
to  avoid long hold times on the j_list_lock. However, since both
functions  contend for j_list_lock, the combined time spent waiting
and processing  can be significant.
jbd2_journal_shrink_checkpoint_list() explicitly calls cond_resched()
when  need_resched() is true to avoid softlockups during prolonged
operations.  But jbd2_log_do_checkpoint() only exits its loop when
need_resched() is  true, relying on potentially sleeping functions
like __flush_batch() or  wait_on_buffer() to trigger rescheduling. If
those functions do not sleep,  the kernel may hit a softlockup.
watchdog: BUG: soft lockup - CPU#3 stuck for 156s!
[kworker/u129:2:373]  CPU: 3 PID: 373 Comm: kworker/u129:2 Kdump:
loaded Not tainted 6.6.0+ #10  Hardware name: Huawei TaiShan 2280
/BC11SPCD, BIOS 1.27 06/13/2017  Workqueue: writeback wb_workfn
(flush-7:2)  pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)  pc : native_queued_spin_lock_slowpath+0x358/0x418  lr :
jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]  Call trace:
native_queued_spin_lock_slowpath+0x358/0x418
jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]
__jbd2_log_wait_for_space+0xfc/0x2f8 [jbd2]
add_transaction_credits+0x3bc/0x418 [jbd2]
start_this_handle+0xf8/0x560 [jbd2]   jbd2__journal_start+0x118/0x228
[jbd2]   __ext4_journal_start_sb+0x110/0x188 [ext4]
ext4_do_writepages+0x3dc/0x740 [ext4]   ext4_writepages+0xa4/0x190
[ext4]   do_writepages+0x94/0x228
__writeback_single_inode+0x48/0x318   writeback_sb_inodes+0x204/0x590
__writeback_inodes_wb+0x54/0xf8   wb_writeback+0x2cc/0x3d8
wb_do_writeback+0x2e0/0x2f8   wb_workfn+0x80/0x2a8
process_one_work+0x178/0x3e8   worker_thread+0x234/0x3b8
kthread+0xf0/0x108   ret_from_fork+0x10/0x20    So explicitly call
cond_resched() in jbd2_log_do_checkpoint() to avoid  softlockup.

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-019113.html");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-032379.html");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109814144/");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:N/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: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-2025-39782");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(20);

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/09/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/27");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1500_cpu_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:simatic_s7-1500_cpu_firmware:3.1.6" :
        {"versionStartIncluding" : "3.1.6", "family" : "S71500", "orderNumbers" : ['6ES7518-4FX00-1AB0', '6ES7518-4AX00-1AC0', '6ES7518-4AX00-1AB0', '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);