CVE-2021-21863 in Development System
Summary
by MITRE • 08/06/2021
A unsafe deserialization vulnerability exists in the ComponentModel Profile.FromFile() functionality of CODESYS GmbH CODESYS Development System 3.5.16 and 3.5.17. A specially crafted file can lead to arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.
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Analysis
by VulDB Data Team • 08/10/2021
The vulnerability identified as CVE-2021-21863 represents a critical unsafe deserialization flaw within the CODESYS Development System version 3.5.16 and 3.5.17. This issue resides in the ComponentModel Profile.FromFile() functionality, which serves as a core component for handling profile data within the industrial automation software environment. The vulnerability stems from the application's improper handling of serialized data structures during the profile loading process, creating a pathway for malicious code execution.
The technical exploitation of this vulnerability occurs through unsafe deserialization practices that allow an attacker to craft a malicious file containing specially formatted serialized data. When the vulnerable system processes this crafted file through the Profile.FromFile() method, the deserialization process inadvertently executes arbitrary commands on the target system. This represents a classic unsafe deserialization attack vector where untrusted data is directly deserialized without proper validation or sanitization, enabling remote code execution capabilities. The flaw aligns with CWE-502, which specifically addresses unsafe deserialization vulnerabilities that can lead to arbitrary code execution through the deserialization of untrusted data.
The operational impact of this vulnerability extends significantly within industrial control system environments where CODESYS is commonly deployed. Attackers can leverage this vulnerability to gain full control over affected systems, potentially leading to unauthorized access to critical infrastructure components. The attack requires only the ability to influence the loading of a profile file, making it particularly dangerous in scenarios where users might process files from untrusted sources or where file upload functionalities exist within the application. This vulnerability can compromise the integrity and availability of industrial automation systems, potentially affecting production processes and operational technology environments.
Organizations utilizing CODESYS Development System should immediately apply the vendor-provided patches and updates to address this vulnerability. System administrators should implement strict file validation procedures and restrict file processing capabilities to trusted sources only. Network segmentation and monitoring of file transfer activities can help detect potential exploitation attempts. The mitigation strategy should include disabling unnecessary file processing functionalities and implementing proper input validation controls. This vulnerability demonstrates the importance of secure coding practices and proper deserialization handling in industrial software systems, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1203 for exploitation for client execution. Organizations should also consider implementing application whitelisting controls to prevent execution of unauthorized binaries and establish comprehensive monitoring for suspicious file processing activities that could indicate exploitation attempts.