CVE-2021-44045 in Drawings SDK
Summary
by MITRE • 12/06/2021
An out-of-bounds write vulnerability exists when reading a DGN file using Open Design Alliance Drawings SDK before 2022.11. The specific issue exists within the parsing of DGN files. Crafted data in a DGN file and lack of proper validation for the XFAT sectors count can trigger a write operation past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process.
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Analysis
by VulDB Data Team • 12/09/2021
The vulnerability identified as CVE-2021-44045 represents a critical out-of-bounds write flaw within the Open Design Alliance Drawings SDK version 2022.10 and earlier releases. This security weakness specifically manifests during the parsing of DGN (Design Graphics Network) files, which are commonly used in computer-aided design applications and engineering workflows. The vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize the XFAT (Extended File Allocation Table) sectors count within DGN file structures. When a maliciously crafted DGN file is processed by the vulnerable SDK, the application attempts to write data beyond the boundaries of a pre-allocated memory buffer, creating a condition that can be exploited for arbitrary code execution.
The technical implementation of this vulnerability aligns with CWE-787, which describes out-of-bounds write conditions that occur when a program writes data past the end of a buffer. The flaw exists in the file parsing logic where the SDK does not validate the XFAT sectors count against the actual file structure limits. This validation failure allows an attacker to construct a DGN file with malformed XFAT data that triggers the buffer overflow condition. The vulnerability operates at the memory management level where the application's buffer allocation does not account for potentially malicious input values, leading to memory corruption that can be leveraged for code execution. The attack vector is particularly concerning as it requires no special privileges beyond the ability to create or access a DGN file, making it exploitable in scenarios where users open untrusted design files.
From an operational perspective, this vulnerability presents significant risk to organizations that rely on Open Design Alliance Drawings SDK for processing design documents, particularly in engineering, architecture, and manufacturing environments. The exploitability of this vulnerability allows an attacker to execute arbitrary code within the context of the application process, potentially leading to complete system compromise. The impact extends beyond individual user systems as design files are frequently shared between organizations, creating opportunities for supply chain attacks. The vulnerability's presence in widely-used CAD software platforms means that successful exploitation could affect numerous enterprise environments, especially those with legacy systems that have not been updated to the patched version. Organizations using the affected SDK version may experience unauthorized access, data exfiltration, or system persistence mechanisms being established by threat actors.
Mitigation strategies for CVE-2021-44045 center around immediate software updates to version 2022.11 or later, which contain the necessary patches to address the buffer validation issue. Security administrators should implement comprehensive patch management procedures to ensure all affected systems receive updates promptly. Additional defensive measures include implementing file validation controls that restrict the types of DGN files that can be processed, particularly those from untrusted sources. Network segmentation and application whitelisting can help limit the potential impact of exploitation by restricting access to vulnerable applications. Organizations should also consider deploying intrusion detection systems that monitor for suspicious file processing activities and implement regular security assessments to identify other potential vulnerabilities in their CAD infrastructure. The ATT&CK framework categorizes this vulnerability under T1059.007 for Windows Scripting and T1566 for spearphishing attachments, highlighting the need for layered security approaches that address both the technical flaw and potential attack vectors.