Siemens COMOS

1. EXECUTIVE SUMMARY

CVSS v3 7.8
ATTENTION: Low attack complexity
Vendor: Siemens
Equipment: COMOS
Vulnerabilities: Memory Allocation with Excessive Size Value, Untrusted Pointer Dereference, Type Confusion, Stack-based Buffer Overflow, Out-of-bounds Write, Out-of-bounds Read, Use After Free, Improper Check for Unusual or Exceptional Conditions

2. RISK EVALUATION

Successful exploitation of these vulnerabilities may result in leaked information or remote code execution in the context of the current process.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Siemens COMOS, a unified platform for collaborative plan design, are affected:

Siemens COMOS: All versions prior to v10.4.1

3.2 VULNERABILITY OVERVIEW

3.2.1 MEMORY ALLOCATION WITH EXCESSIVE SIZE VALUE CWE-789

Open Design Alliance Drawings SDK before 2021.12 contains a memory allocation with excessive size vulnerability when parsing specially crafted DGN files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-25173 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.2 MEMORY ALLOCATION WITH EXCESSIVE SIZE VALUE CWE-789

CVE-2021-25174 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.3 UNTRUSTED POINTER DEREFERENCE CWE-822

Open Design Alliance Drawings SDK before 2021.11 contains a type conversion vulnerability when parsing specially crafted DXF and DWG files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-25175 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.4 UNTRUSTED POINTER DEREFERENCE CWE-822

Open Design Alliance Drawings SDK before 2021.11 contains a NULL pointer dereference vulnerability when parsing DXF and DWG files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-25176 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.5 ACCESS OF RESOURCE USING INCOMPATIBLE TYPE (‘TYPE CONFUSION') CWE-843

Open Design Alliance Drawings SDK before 2021.11 contains a type confusion issue when parsing specially crafted DXF and DWG files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-25177 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.6 STACK-BASED BUFFER OVERFLOW CWE-121

Open Design Alliance Drawings SDK before 2021.11 contains a stack-based buffer overflow vulnerability when parsing specially crafted DXF or DWG files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-25178 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.7 OUT-OF-BOUNDS WRITE CWE-787

Open Design Alliance Drawings SDK before 2021.6 contains an out-of-bounds write issue when parsing specially crafted DXF files. This could result in a write past the end of an allocated buffer and allow an attacker to execute code in the context of the current process.

CVE-2021-31784 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.8 OUT-OF-BOUNDS WRITE CWE-787

Open Design Alliance Drawings SDK before 2022.4 contains an out-of-bounds write issue when parsing specially crafted DXF files. This could result in a write past the end of an allocated buffer and allow an attacker to execute code in the context of the current process.

CVE-2021-32936 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.9 OUT-OF-BOUNDS READ CWE-125

Open Design Alliance Drawings SDK before 2022.4 are vulnerable to an out-of-bounds read when parsing specially crafted DWG files. This could allow an attacker to read sensitive information from memory locations and to cause a denial-of-service condition.

CVE-2021-32938 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.10 OUT-OF-BOUNDS READ CWE-125

CVE-2021-32940 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.11 USE AFTER FREE CWE-416

Open Design Alliance Drawings SDK before 2021.11 contains a use-after-free vulnerability when parsing specially crafted DGN files. This could allow an attacker to execute code in the context of the current process.

CVE-2021-32944 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.12 IMPROPER CHECK FOR UNUSUAL OR EXCEPTIONAL CONDITIONS CWE-754

Open Design Alliance Drawings SDK before 2022.4 are vulnerable to improper check for unusual or exceptional conditions when parsing specially crafted DGN files. This could allow an attacker to cause a denial-of-service condition or execute code in the context of the current process.

CVE-2021-32946 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.13 OUT-OF-BOUNDS WRITE CWE-787

Open Design Alliance Drawings SDK before 2022.4 contains an out-of-bounds write issue when parsing specially crafted DWG files. This could result in a write past the end of an allocated buffer and allow an attacker to execute code in the context of the current process.

CVE-2021-32948 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.14 OUT-OF-BOUNDS READ CWE-125

Open Design Alliance Drawings SDK before 2022.4 are vulnerable to an out-of-bounds read when parsing specially crafted DXF files. This could allow an attacker to read sensitive information from memory locations and to cause a denial-of-service condition.

CVE-2021-32950 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.15 OUT-OF-BOUNDS WRITE CWE-787

Open Design Alliance Drawings SDK before 2022.4 contains an out-of-bounds write issue when parsing specially crafted DGN files. This could result in a write past the end of an allocated buffer and allow an attacker to execute code in the context of the current process.

CVE-2021-32952 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors
COUNTRIES/AREAS DEPLOYED: Worldwide
COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens reported these vulnerabilities to CISA.

4. MITIGATIONS

Siemens recommends upgrading the following software to the most current version:

COMOS: Update to v10.4.1 or later

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

Avoid to open untrusted files from unknown sources in COMOS
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 users configure the environment according to the Siemens operational guidelines for industrial security and follow the recommendations in the product manuals

For additional information, please refer to Siemens Security Advisory SSA-155599

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet.
Locate control system networks and remote devices behind firewalls and isolate them from the business network.
When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

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 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 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 these vulnerabilities. These vulnerabilities are not exploitable remotely.

This product is provided subject to this Notification and this Privacy & Use policy.

Vendor

Siemens