Full Report
Multiple vulnerabilities were found in SIMATIC WinCC that ultimately could allow local or remote attackers to escalate privileges and read, write or delete critical files. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens is preparing further updates and recommends specific countermeasures for products where updates are not, or not yet available. Note: The vulnerability CVE-2021-40359 is part of a shared component, used by various Siemens products (SIMATIC Communication Services - SCS). The installation of a fix version of any product also removes the vulnerability for other products on the same system, even if those products were not updated.
Analysis Summary
# Vulnerability: Multiple Privilege Escalation and File Manipulation Flaws in SIMATIC WinCC
## CVE Details
*Note: While the provided text mentions CVE-2021-40359 specifically, the summary covers the scope of the "multiple vulnerabilities" described.*
- **CVE ID:** CVE-2021-40359 (Primary), others referenced as "Multiple"
- **CVSS Score:** Critical/High (Typical for Privilege Escalation and Remote File Access)
- **CWE:** Not explicitly listed in text, but likely CWE-269 (Improper Privilege Management) and CWE-73 (External Control of File Name or Path).
## Affected Systems
- **Products:**
- SIMATIC WinCC
- SIMATIC Communication Services (SCS) - *Shared component*
- Other Siemens products utilizing the SCS component.
- **Versions:** Multiple versions are affected. Specific impacted versions are those preceding the "fix versions" released by Siemens.
- **Configurations:** Systems where SIMATIC Communication Services (SCS) is installed and active.
## Vulnerability Description
The vulnerabilities exist within SIMATIC WinCC and its shared component, SIMATIC Communication Services (SCS). The flaws allow an attacker to bypass existing security controls to escalate their privileges on the system. Furthermore, the vulnerabilities enable unauthorized operations on the file system, specifically allowing an attacker to read, write, or delete critical system or application files. Because SCS is a shared component, a vulnerability in this service impacts all Siemens software on the host that relies on it.
## Exploitation
- **Status:** Not specified as "in the wild" in the provided text, but addressed as a significant risk.
- **Complexity:** Medium (Implied by the requirement for local or remote access depending on the specific flaw).
- **Attack Vector:** Local or Remote.
## Impact
- **Confidentiality:** **High** (Attackers can read critical files).
- **Integrity:** **High** (Attackers can write/modify critical files and escalate privileges).
- **Availability:** **High** (Attackers can delete critical files, leading to system instability or denial of service).
## Remediation
### Patches
- Siemens has released updates for several affected products. Users are advised to update to the latest available versions immediately.
- **Shared Fix:** Installing a fix version for *any* product using the SCS component effectively patches the vulnerability for all other Siemens products on that specific system.
### Workarounds
- **Countermeasures:** For products where updates are not yet available, Siemens recommends implementing specific countermeasures (e.g., restricting network access, applying principle of least privilege).
- **Isolation:** Minimize exposure of affected systems to the corporate network or internet.
## Detection
- **Indicators of Compromise:** Monitor for unusual file system activity (unexpected deletions or modifications) and unauthorized attempts to elevate user privileges.
- **Detection methods:** Audit logs for SIMATIC WinCC and SCS; integrity checks on critical system files.
## References
- **Siemens ProductCERT:** hxxps[://]www[.]siemens[.]com/cert/advisories
- **Component Advisory:** CVE-2021-40359 Reference within Siemens Security Advisories.