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1. EXECUTIVE SUMMARY
- CVSS v3 7.8
- ATTENTION: Low skill level to exploit
- Vendor: Siemens
- Equipment: DIGSI 4
- Vulnerability: Incorrect Default Permissions
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow a low privileged attacker to execute arbitrary code with SYSTEM privileges.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following Siemens products are affected:
- DIGSI 4: All versions prior to v4.94 SP1 HF 1
3.2 VULNERABILITY OVERVIEW
Several folders in the %PATH% are writeable by normal users. As these folders are included in the search for DLLs, an attacker could place a DLL file with code executed by SYSTEM.
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Germany
Rich Davy from ECSC Group reported this vulnerability to Siemens.
Siemens has released updates, which are recommended to be applied when possible:
- DIGSI 4: Update to v4.94 SP1 HF 1 or later version
As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the environment according to Siemens’ operational guidelines for industrial security, and follow the recommendations in the product manuals.
Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity
For more information see Siemens security advisory SSA-536315
CISA also recommends users take the following measures to protect themselves from social engineering attacks:
- Do not click web links or open unsolicited attachments in email messages.
- Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
- Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.
CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. 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 on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely.
For any questions related to this report, please contact the CISA at:
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