Siemens SIMATIC S7-1500 Heap-based Buffer Overflow (CVE-2023-38545)

high Tenable OT Security Plugin ID 503932

Synopsis

The remote OT asset is affected by a vulnerability.

Description

This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake. When curl is asked to pass along the hostname to the SOCKS5 proxy to allow that to resolve the address instead of it getting done by curl itself, the maximum length that hostname can be is 255 bytes. If the hostname is detected to be longer than 255 bytes, curl switches to local name resolving and instead passes on the resolved address only to the proxy. Due to a bug, the local variable that means let the host resolve the name could get the wrong value during a slow SOCKS5 handshake, and contrary to the intention, copy the too long hostname to the target buffer instead of copying just the resolved address there.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 503932

Version: 1.2

Type: remote

Family: Tenable.ot

Published: 11/13/2025

Updated: 11/13/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: High

Score: 8.9

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 2/13/2024

Vulnerability Publication Date: 2/13/2024

Reference Information

CVE: CVE-2023-38545

CWE: 122

ICSA: 23-348-10

Detections

Analytics