CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
Percentile
65.2%
Siemens has released a firmware update to mitigate an insufficient entropy vulnerability that affects Siemens Desigo PX Web modules. Marcella Hastings, Joshua Fried, and Nadia Heninger from the University of Pennsylvania coordinated this vulnerability directly with Siemens.
This vulnerability could be exploited remotely.
Siemens reports that this vulnerability affects the following Desigo PX Web modules and versions:
A successful exploitation of this vulnerability could allow an attacker to recover private keys used for HTTPS in the integrated web server.
Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.
Siemens is a multinational company headquartered in Munich, Germany.
The affected products, Desigo PX modules, control and monitor building automation systems. According to Siemens, Desigo PX Web modules are deployed in the Commercial Facilities sector. Siemens estimates that these products are used worldwide.
The affected devices use a pseudo random number generator with insufficient entropy to generate certificates for HTTPS, potentially allowing remote attackers to reconstruct the corresponding private key.
CVE-2016-9154NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9154, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed December 20, 2016.
This vulnerability could be exploited remotely.
No known public exploits specifically target this vulnerability.
Crafting a working exploit for this vulnerability would be difficult.
Siemens provides firmware update V6.00.046 for the affected devices, which fixes the vulnerability. Siemens recommends that all users operating an affected device apply the update.
The firmware updates for Desigo PX Web modules can be obtained from:
<https://support.industry.siemens.com/cs/ww/en/view/109742824>
Until patches can be applied, Siemens recommends the following:
For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-856492 at the following location:
<http://www.siemens.com/cert/advisories>
ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT web page. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available in the ICSβCERT Technical Information Paper, ICS-TIP-12-146-01BβTargeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to ICS-CERT for tracking and correlation against other incidents.
www.siemens.com/cert/advisories
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CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
Percentile
65.2%