CVE-2021-34876 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-14828.
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Analysis
by VulDB Data Team • 01/17/2022
CVE-2021-34876 represents a critical buffer overflow vulnerability affecting Bentley View version 10.15.0.75, which falls under the Common Weakness Enumeration category CWE-121 as a stack-based buffer overflow. This vulnerability specifically manifests during the parsing of JT files, which are proprietary 3D file formats used extensively in engineering and construction software. The flaw occurs when the application processes maliciously crafted data within JT files, causing the software to write beyond the bounds of an allocated buffer in memory. This type of vulnerability is particularly dangerous because it can be exploited through social engineering techniques where users must visit a malicious webpage or open a crafted file to trigger the exploit. The vulnerability exists in the memory management routines that handle JT file parsing, where insufficient bounds checking allows an attacker to overwrite adjacent memory locations. When exploited, this vulnerability enables remote code execution with the privileges of the current user process, effectively allowing attackers to execute arbitrary code on the target system. The attack vector requires user interaction, making it a client-side vulnerability that relies on user trust and social engineering rather than direct network exploitation. This vulnerability aligns with ATT&CK technique T1203 which describes exploitation for client execution, where adversaries leverage vulnerabilities in software applications to gain code execution. The impact of this vulnerability extends beyond simple code execution as it can potentially allow attackers to escalate privileges, install backdoors, or access sensitive data stored within the application context. The vulnerability was identified and tracked as ZDI-CAN-14828, highlighting its significance in the cybersecurity community's vulnerability tracking systems. The specific nature of the buffer overflow in JT file parsing indicates a lack of proper input validation and memory boundary checking within the application's file processing pipeline. This type of vulnerability is particularly concerning in engineering software environments where users frequently handle third-party files and collaborate on complex projects. The exploitability of this vulnerability is enhanced by the widespread use of JT files in professional engineering workflows, making it a prime target for attackers seeking to compromise engineering and construction firms. The vulnerability demonstrates the importance of robust input validation and memory safety practices in software development, particularly for applications that process complex file formats from untrusted sources. Organizations using Bentley View should consider immediate remediation through official patches and updates provided by the vendor to prevent potential exploitation. The vulnerability also underscores the need for comprehensive security testing of file parsing components and the implementation of memory safety mechanisms such as stack canaries, address space layout randomization, and control flow integrity to mitigate similar risks in future software releases.
The vulnerability presents a significant risk to organizations that rely heavily on Bentley View for engineering and construction documentation, as JT files are commonly shared between different stakeholders in these industries. The requirement for user interaction makes this vulnerability particularly challenging to defend against through network-based security measures alone, as it necessitates user education and awareness training to prevent successful exploitation. Security professionals should consider implementing application whitelisting policies that restrict the execution of potentially malicious files and establish strict protocols for handling third-party JT files. The vulnerability's classification as a buffer overflow highlights the critical need for developers to implement proper bounds checking and input validation mechanisms, especially when processing binary file formats that may contain embedded data structures. This particular vulnerability serves as a reminder of the importance of secure coding practices and the potential consequences of inadequate memory management in commercial software applications. Organizations should also consider network segmentation and monitoring to detect anomalous behavior that might indicate exploitation attempts, as the vulnerability could be leveraged for more sophisticated attack campaigns targeting specific engineering environments. The vulnerability's impact is amplified by the fact that successful exploitation can lead to complete system compromise, particularly in environments where engineering software runs with elevated privileges or has access to sensitive project data.