1. EXECUTIVE SUMMARY

  • CVSS v3 7.3
  • ATTENTION: Low skill level to exploit
  • Vendor: Siemens
  • Equipment: Automation License Manager (ALM)
  • Vulnerability: Improper Authorization

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to locally escalate privileges and modify files that should be protected against writing.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Automation License Manager (ALM), a software management platform, are affected:

  • Automation License Manager 5: All versions
  • Automation License Manager 6: All versions prior to v6.0.8

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER AUTHORIZATION CWE-285

The application does not properly validate the users’ privileges when executing some operations, which could allow an attacker with low permissions to arbitrarily modify files that should be protected against writing.

CVE-2020-7583 has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Chemical, Energy, Food and Agriculture, and Water and Wastewater Systems
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Lasse Trolle Borup of Danish Cyber Defense reported this vulnerability to Siemens.

4. MITIGATIONS

Siemens recommends the following:

  • Users of License Manager 5: Disable access to drives which have licenses installed, for non-administrator users.
  • Users of License Manager 6: Update to v6.0.8 or later version.

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for Industrial Security, and to follow the recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory SSA-388646
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.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.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.

Source:

https://us-cert.cisa.gov/ics/advisories/icsa-20-224-07