CVE-2021-27381 in Solid Edge SE2020
Summary
by MITRE • 03/16/2021
A vulnerability has been identified in Solid Edge SE2020 (All Versions < SE2020MP13), Solid Edge SE2021 (All Versions < SE2021MP3). Affected applications lack proper validation of user-supplied data when parsing PAR files. This could result in an out of bounds read past the end of an allocated structure. An attacker could leverage this vulnerability to execute code in the context of the current process. (ZDI-CAN-12534)
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Analysis
by VulDB Data Team • 04/01/2021
This vulnerability exists in Siemens Solid Edge software versions prior to specific maintenance releases, representing a critical security flaw that could enable remote code execution. The issue stems from insufficient input validation mechanisms within the PAR file parsing functionality, which is commonly used for storing project data and configuration information. The vulnerability specifically affects Solid Edge SE2020 versions before MP13 and SE2021 versions before MP3, indicating a widespread impact across multiple product lines and release cycles.
The technical flaw manifests as an out-of-bounds read condition that occurs when the application processes malformed PAR files without proper bounds checking. This type of vulnerability falls under the CWE-129 category of Improper Validation of Array Index, where the software fails to validate the size or range of array indices before accessing memory locations. The parsing routine does not adequately verify the structure of incoming data, allowing an attacker to craft malicious PAR files that cause the application to read memory beyond the allocated buffer boundaries. This memory access violation creates a predictable exploitation vector that can be leveraged to execute arbitrary code with the privileges of the running process.
The operational impact of this vulnerability is severe as it enables attackers to achieve remote code execution without requiring authentication or elevated privileges. An attacker could deliver a malicious PAR file through various attack vectors including email attachments, web downloads, or compromised file sharing systems. Once opened by an unsuspecting user, the vulnerable Solid Edge application would parse the malicious file and trigger the out-of-bounds read condition, potentially allowing remote code execution. This represents a significant threat to engineering and design environments where Solid Edge is commonly used, as these systems often contain sensitive intellectual property and critical design data.
The exploitation of this vulnerability aligns with ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage software vulnerabilities to execute malicious code on target systems. Organizations using Solid Edge in their design workflows face particular risk as these applications are often run with elevated privileges during design processes. The vulnerability's impact extends beyond simple code execution to potentially compromise entire design environments, as attackers could access or modify sensitive engineering data while maintaining persistent access through the executed code. Security teams should prioritize patching affected systems and implementing network segmentation to limit potential attack vectors.
Mitigation strategies should include immediate application of the vendor-provided patches for SE2020MP13 and SE2021MP3 releases, which address the input validation issues in PAR file parsing. Organizations should also implement strict file validation policies, particularly for incoming files from untrusted sources, and consider deploying application whitelisting solutions to prevent execution of unauthorized PAR files. Network-based protections such as intrusion detection systems and firewalls should be configured to monitor for suspicious file transfer activities. Additionally, user awareness training should emphasize the risks of opening unknown or untrusted files, as social engineering remains a common delivery method for such exploits. Regular security assessments of engineering environments should include verification of patched software versions and monitoring for unauthorized software installations that might introduce similar vulnerabilities.