PT-2013-44: Forced browsing in Siemens WinCC and SIMATIC PCS 7

(PT-2013-44) Positive Technologies Security Advisory
Forced browsing in Siemens WinCC and SIMATIC PCS 7

Vulnerable software

Siemens WinCC
Version: 7.2 and earlier

Version: 8.0 SP1 and earlier

Application link:

Severity level

Severity level: Medium
Impact: Username Access
Access Vector: Remote  

CVSS v2:
Base Score: 4.0
Vector: (AV:N/AC:L/Au:S/C:P/I:N/A:N)

CVE: CVE-2013-3959

Software description

Siemens WinCC is a part of Siemens SIMATIC HMI software that aimed to provide connection between an operator and PLCs that manage technological processes. The WebNavigator component of WinCC gives the users the possibility to control their plants via the web browser with the same look-and-feel like local operator stations.

Vulnerability description

The specialists of the Positive Research center have detected a vulnerability, which can be used to gain access to usernames in Siemens WinCC and SIMATIC PCS 7.

The WinCC Web Navigator 7.2 allows a user with authenticated access to probe for valid NetBIOS user names by manipulating URL parameters. This could allow the attacker to obtain user names with heightened privileges.

How to fix

Update your software up to the latest version

Advisory status

13.01.2013 - Vendor gets vulnerability details
14.06.2013 - Vendor releases fixed version and details
03.07.2013 - Public disclosure


The vulnerability was detected by Alexander Tlyapov, Positive Research Center (Positive Technologies Company)


Reports on the vulnerabilities previously discovered by Positive Research:

About Positive Technologies

Positive Technologies is among the key players in the IT security market in Russia.

The principal activities of the company include the development of integrated tools for information security monitoring (MaxPatrol); providing IT security consulting services and technical support; development of the Securitylab leading Russian information security portal.

Among the clients of Positive Technologies, there are more than 40 state enterprises, more than 50 banks and financial organizations, 20 telecommunication companies, more than 40 plant facilities, as well as IT, service and retail companies from Russia, the CIS countries, the Baltic States, China, Ecuador, Germany, Great Britain, Holland, Iran, Israel, Japan, Mexico, the Republic of South Africa, Thailand, Turkey, and the USA.

Positive Technologies is a team of highly skilled developers, advisers and experts with years of vast hands-on experience. The company specialists possess professional titles and certificates; they are the members of various international societies and are actively involved in the IT security field development.