CVE-2021-34928 in View
Summary
by MITRE • 01/14/2022
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Bentley View 10.15.0.75. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of JT files. Crafted data in a JT file can trigger a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-14906.
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Analysis
by VulDB Data Team • 01/17/2022
CVE-2021-34928 represents a critical buffer overflow vulnerability affecting Bentley View version 10.15.0.75 that enables remote code execution through malicious JT file manipulation. This vulnerability falls under CWE-121, heap-based buffer overflow, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The flaw specifically manifests during the parsing of JT (JT Open) files, which are proprietary 3D CAD file formats used extensively in engineering and construction industries. When a maliciously crafted JT file is processed by the vulnerable Bentley View application, the buffer overflow occurs during memory allocation and data handling operations, allowing attackers to write beyond the allocated buffer boundaries.
The exploitation requires user interaction through either visiting a malicious webpage hosting the crafted JT file or opening the malicious file directly, making this a client-side attack vector that leverages social engineering techniques. This vulnerability operates at the application layer and can be classified under ATT&CK tactic TA0002 (execution) with sub-technique T1059.007. The buffer overflow enables attackers to execute arbitrary code within the context of the current process, potentially leading to full system compromise. The vulnerability's impact extends beyond simple code execution as it can allow attackers to escalate privileges, access sensitive data, or establish persistent access to affected systems. The attack surface is particularly concerning given Bentley View's widespread use in critical infrastructure sectors including architecture, engineering, and construction where the software handles sensitive project data and designs.
The technical implementation of this vulnerability demonstrates poor input validation and memory management practices within the JT file parser component of Bentley View. When processing JT files, the application fails to properly validate the size and structure of data elements, leading to predictable buffer overflow conditions. This type of vulnerability is particularly dangerous because it can be triggered through web-based attacks, allowing attackers to deliver malicious payloads through compromised websites or email attachments. The vulnerability's classification as a heap-based buffer overflow (CWE-121) indicates that the application allocates memory on the heap and fails to properly bounds-check data before writing to allocated memory regions. Security professionals should note that this vulnerability is part of a broader class of memory corruption flaws that have historically been primary attack vectors for advanced persistent threats and zero-day exploits. Organizations using Bentley View software should prioritize immediate patching and implement network segmentation controls to limit the potential impact of such attacks.
The operational impact of CVE-2021-34928 extends beyond immediate exploitation as it represents a significant risk to industrial control systems and engineering workflows. Given that Bentley View is commonly used in critical infrastructure sectors, successful exploitation could potentially compromise design integrity, access confidential project information, or even enable attackers to manipulate engineering data that affects physical systems. The vulnerability's requirement for user interaction makes it less likely to be exploited at scale compared to fully automated attacks, but it remains a serious concern for targeted attacks against specific organizations. From a defensive perspective, organizations should implement multiple layers of protection including web application firewalls, email filtering controls, and user education programs to reduce the likelihood of successful exploitation. The vulnerability also highlights the importance of proper software supply chain security and regular security assessments of third-party applications used in critical business processes, particularly those handling sensitive data and complex file formats.