CVE-2021-34873

Vulnerability

This vulnerability affects Bentley View version 10.15.0.75 and earlier versions prior to 10.16.02.* [1][2]. The bug resides in the parsing of PDF files, specifically a write past the end of an allocated buffer occurs when crafted data is processed [1]. User interaction is required, as the target must open a malicious PDF file or visit a malicious page [1].

Exploitation

An attacker can exploit this vulnerability by convincing a user to open a specially crafted PDF file using an affected version of Bentley View [1]. No authentication is needed, but the user must perform the action of opening the file [1]. The exploit leverages the out-of-bounds write during PDF parsing to achieve arbitrary code execution [1][2].

Impact

Successful exploitation allows an attacker to execute arbitrary code in the context of the current process [1]. This can lead to full disclosure of sensitive information, modification of data, or denial of service, with the highest confidentiality, integrity, and availability impact [1]. No privilege escalation beyond the current user is indicated.

Mitigation

Bentley released a fix in version 10.16.02.* and more recent versions of Bentley View [2]. Users should update to the latest version as soon as possible. As a general best practice, only open PDF files from trusted sources [2]. No other workarounds are provided in the available references.