Authentication Bypass Vulnerability in SIMATIC CP and TIM Devices

Act Now9.8SSA-763427Nov 27, 2015

Attack VectorNetwork

Auth RequiredNone

ComplexityLow

User InteractionNone needed

Summary

SIMATIC CP and TIM devices contain an authentication bypass vulnerability (CWE-306) that allows unauthenticated remote attackers to perform administrative operations on affected communication processors and telecontrol modules. Successful exploitation requires only network access to the device; no credentials or user interaction are needed. This affects the CP 342-5, CP 343-1, CP 443-1, CP 443-5, and TIM 3V-IE/4R-IE product lines across standard and SIPLUS NET variants. Several product variants lack vendor patches and require compensating controls.

What this means

What could happen

An attacker who reaches a vulnerable CP or TIM device over the network can bypass authentication and perform administrative operations, such as reconfiguring communication parameters, halting data collection, or altering network settings without credentials.

Who's at risk

Water utilities and electric distribution operators using Siemens SIMATIC CP communication processors or TIM telecontrol interface modules for SCADA data collection, remote terminal unit communication, or network management. Specifically affects CP 343, CP 443, CP 342-5, TIM 3V-IE, and TIM 4R-IE devices in industrial automation networks.

How it could be exploited

An attacker sends specially crafted network requests to the CP/TIM device on its management port (typically port 102 or similar, depending on device configuration). The device fails to properly validate authentication, allowing the attacker to execute administrative commands directly. No credentials or special conditions are required beyond network reachability.

Prerequisites

Network access to the CP/TIM device management interface port
No valid credentials required

remotely exploitableno authentication requiredlow complexitycritical severity (CVSS 9.8)no patch available for several product lines (CP 342-5, CP 443-5)affects network control devices

Exploitability

Moderate exploit probability (EPSS 1.4%)

Affected products (25)

19 with fix6 pending

ProductAffected VersionsFix Status

SIMATIC CP 342-5All versionsNo fix yet

SIMATIC CP 342-5 FOAll versionsNo fix yet

SIMATIC CP 343-1< V3.1.13.1.1

SIMATIC CP 343-1 Advanced< V3.0.443.0.44

SIMATIC CP 343-1 Lean< V3.1.13.1.1

Remediation & Mitigation

0/21

Do now

0/1

WORKAROUNDFor unpatched CP 342-5, CP 342-5 FO, CP 443-5, and SIPLUS NET CP/TIM 443-5 products: restrict network access to management interfaces using firewall rules and network segmentation; limit access to trusted engineering workstations only

Schedule — requires maintenance window

0/19

Patching may require device reboot — plan for process interruption

Long-term hardening

0/1

HARDENINGImplement network segmentation to isolate CP and TIM devices from untrusted networks; place these devices on separate VLAN with restricted access policies

CVEs (1)

CVE-2015-8214

View full Siemens ProductCERT advisory

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