CVE-2021-46630 in View
Summary
by MITRE • 02/18/2022
This vulnerability allows remote attackers to disclose sensitive information 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 FBX files. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process. Was ZDI-CAN-15460.
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Analysis
by VulDB Data Team • 02/19/2022
This vulnerability represents a critical security flaw in Bentley View version 10.15.0.75 that enables remote information disclosure through improper handling of FBX file parsing operations. The vulnerability stems from inadequate input validation mechanisms within the software's file processing pipeline, specifically when handling Autodesk FBX format files. The flaw manifests as a buffer overread condition that occurs during the parsing of maliciously crafted FBX content, allowing attackers to access memory regions beyond the intended buffer boundaries.
The technical implementation of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where programs access memory locations outside the bounds of allocated buffers. The vulnerability requires user interaction to be exploited effectively, as victims must visit a malicious webpage or open a specially crafted FBX file. This user interaction requirement places the attack in the ATT&CK framework category of initial access through malicious files or web content. The buffer overread condition creates a predictable memory access pattern that can be leveraged to extract sensitive data from adjacent memory locations, potentially including stack contents, heap data, or other process information.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with foundational capabilities for more sophisticated attacks. The extracted memory contents may include pointers, credentials, encryption keys, or other sensitive data that could be used to escalate privileges or execute arbitrary code within the application context. Attackers can potentially chain this vulnerability with other exploits to achieve full system compromise, as noted in the original vulnerability identification ZDI-CAN-15460. The vulnerability affects the core file processing functionality of Bentley View, making it particularly dangerous given the software's widespread use in engineering and construction environments where sensitive project data is commonly processed.
Mitigation strategies should focus on immediate patching of affected systems to address the buffer overread condition in FBX file parsing. Organizations should implement strict file validation procedures that verify FBX file integrity before processing, including checking file headers, structure consistency, and size limitations. Network-level controls such as web application firewalls and content filtering solutions can help prevent access to malicious FBX files through web interfaces. Additionally, user education regarding the dangers of opening untrusted files from unknown sources remains crucial. Security monitoring should include detection of unusual memory access patterns or file processing activities that could indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation and proper bounds checking in file format parsers, particularly in applications handling sensitive engineering data where security breaches could have significant operational and financial consequences.