SSA-730482

Siemens Security Advisory by Siemens ProductCERT

SSA-730482: Denial of Service Vulnerability in SIMATIC WinCC

Publication Date:	2024-04-09
Last Update:	2024-07-09
Current Version:	V1.1
CVSS v3.1 Base Score:	6.2
CVSS v4.0 Base Score:	6.9

SUMMARY

A vulnerability in the login dialog box of SIMATIC WinCC could allow a local attacker to cause a denial of service condition in the runtime of the SCADA system.

Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.

AFFECTED PRODUCTS AND SOLUTION

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Affected Product and Versions	Remediation
SIMATIC PCS 7 V9.1 All versions < V9.1 SP2 UC04 affected by CVE-2023-50821	Update to V9.1 SP2 UC04 or later version https://support.industry.siemens.com/cs/ww/en/view/109812242/ See further recommendations from section Workarounds and Mitigations
SIMATIC WinCC Runtime Professional V17 All versions affected by CVE-2023-50821	Currently no fix is available See recommendations from section Workarounds and Mitigations
SIMATIC WinCC Runtime Professional V18 All versions < V18 Update 4 affected by CVE-2023-50821	Update to V18 Update 4 or later version https://support.industry.siemens.com/cs/ww/en/view/109807225/ See further recommendations from section Workarounds and Mitigations
SIMATIC WinCC Runtime Professional V19 All versions < V19 Update 1 affected by CVE-2023-50821	Update to V19 Update 1 or later version https://support.industry.siemens.com/cs/ww/en/view/109820999/ See further recommendations from section Workarounds and Mitigations
SIMATIC WinCC V7.5 All versions < V7.5 SP2 Update 16 affected by CVE-2023-50821	Update to V7.5 SP2 Update 16 or later version https://support.industry.siemens.com/cs/ww/en/view/109793460/ See further recommendations from section Workarounds and Mitigations
SIMATIC WinCC V8.0 All versions < V8.0 Update 5 affected by CVE-2023-50821	Update to V8.0 Update 5 or later version https://support.industry.siemens.com/cs/ww/en/view/109818723/ See further recommendations from section Workarounds and Mitigations

WORKAROUNDS AND MITIGATIONS

Siemens has identified the following specific workarounds and mitigations that customers can apply to reduce the risk:

Activate SIMATIC Logon in the User Administrator of the SIMATIC PCS 7 Operator Stations

Product-specific remediations or mitigations can be found in the section Affected Products and Solution.
Please follow the General Security Recommendations.

GENERAL SECURITY RECOMMENDATIONS

As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens' operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity

PRODUCT DESCRIPTION

SIMATIC PCS 7 is a distributed control system (DCS) integrating SIMATIC WinCC, SIMATIC Batch, SIMATIC Route Control, OpenPCS 7 and other components.

SIMATIC WinCC is a supervisory control and data acquisition (SCADA) system.

SIMATIC WinCC Runtime Professional is a visualization runtime platform used for operator control and monitoring of machines and plants.

VULNERABILITY DESCRIPTION

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This chapter describes all vulnerabilities (CVE-IDs) addressed in this security advisory. Wherever applicable, it also documents the product-specific impact of the individual vulnerabilities.

Vulnerability CVE-2023-50821

The affected products do not properly validate the input provided in the login dialog box. An attacker could leverage this vulnerability to cause a persistent denial of service condition.

CVSS v3.1 Base Score	6.2
CVSS v3.1 Vector	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C
CVSS v4.0 Base Score	6.9
CVSS v4.0 Vector	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CWE	CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

ACKNOWLEDGMENTS

Siemens thanks the following party for its efforts:

Doukani Mohammed Adam from Resilience (resilience.sa) for reporting the vulnerability

ADDITIONAL INFORMATION

For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories

HISTORY DATA

V1.0 (2024-04-09):	Publication Date
V1.1 (2024-07-09):	Added fix for SIMATIC WinCC V8.0 and SIMATIC WinCC Runtime Professional V18

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