CVE-2021-34877 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-14829.
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Analysis
by VulDB Data Team • 01/17/2022
CVE-2021-34877 represents a critical buffer overflow vulnerability affecting Bentley View version 10.15.0.75, classified under CWE-121 as a 'Stack-based Buffer Overflow' within the JT file parsing component. This vulnerability arises from insufficient bounds checking during the processing of JT (JT file format) which is a proprietary 3D graphics format used for visualization in engineering and construction software. The flaw occurs when the application attempts to write data beyond the allocated memory buffer boundaries, creating a condition where maliciously crafted data can overwrite adjacent memory locations.
The attack vector requires user interaction through either visiting a malicious webpage or opening a specially crafted JT file, making this a client-side exploitation scenario. According to ATT&CK framework category T1203, this vulnerability aligns with 'Exploitation for Client Execution' where adversaries leverage application vulnerabilities to execute code on targeted systems. The buffer overflow specifically targets the memory management during JT file parsing, allowing an attacker to manipulate the program's execution flow by overwriting return addresses or function pointers in the call stack.
The operational impact of this vulnerability extends beyond simple code execution, as it operates within the context of the current process, potentially enabling privilege escalation depending on the application's execution permissions. Attackers can leverage this vulnerability to inject malicious code that executes with the same privileges as the Bentley View application, which typically runs with user-level permissions but may have elevated access in enterprise environments. This vulnerability affects organizations heavily reliant on engineering visualization software where JT files are commonly shared between teams and departments.
Mitigation strategies should focus on immediate patching of affected Bentley View installations to version 10.15.0.76 or later, as this represents the primary defense against exploitation. Network administrators should implement content filtering measures to prevent users from accessing untrusted JT files through web browsers or email attachments. Additionally, organizations should consider implementing application whitelisting policies that restrict execution of unauthorized binaries, particularly in high-risk environments. The vulnerability demonstrates the importance of input validation and memory safety practices, aligning with industry standards that emphasize secure coding practices to prevent buffer overflow conditions. Regular security assessments of third-party software components and maintaining updated threat intelligence on similar vulnerabilities in engineering visualization tools should form part of comprehensive cybersecurity defense strategies.