CVE-2018-3932 in Office Server
Summary
by MITRE
An exploitable stack-based buffer overflow exists in the Microsoft Word document conversion functionality of the Antenna House Office Server Document Converter version V6.1 Pro MR2 for Linux64 (6,1,2018,0312). A crafted Microsoft Word (DOC) document can lead to a stack-based buffer overflow, resulting in remote code execution.
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Analysis
by VulDB Data Team • 04/06/2023
The vulnerability identified as CVE-2018-3932 represents a critical stack-based buffer overflow flaw within the Antenna House Office Server Document Converter version V6.1 Pro MR2 for Linux64. This converter serves as a document processing component that handles Microsoft Word document conversions, making it a potential attack vector for remote code execution. The flaw specifically manifests during the conversion of DOC files, where the application fails to properly validate input data lengths before copying data to fixed-size buffers on the stack. The vulnerability stems from inadequate bounds checking mechanisms that allow maliciously crafted input to exceed the allocated buffer space, causing a classic stack overflow condition.
The technical exploitation of this vulnerability occurs when a specially crafted Microsoft Word document is processed by the converter application. The malicious document contains input data that exceeds the predetermined buffer limits, causing the stack memory to be overwritten with attacker-controlled data. This overflow can corrupt the return addresses and execution flow of the program, potentially allowing an attacker to execute arbitrary code with the privileges of the converter process. The vulnerability is particularly concerning as it operates in a server environment where the converter may process documents from untrusted sources, making remote code execution a realistic threat. The stack-based nature of the overflow provides attackers with predictable memory layout characteristics that facilitate exploitation techniques such as return-oriented programming and stack pivoting.
From an operational impact perspective, this vulnerability creates significant security risks for organizations utilizing the Antenna House Office Server Document Converter in production environments. The remote code execution capability means that attackers could potentially gain full control over the affected system without requiring local access or authentication. This vulnerability directly impacts the confidentiality, integrity, and availability of the affected systems, as successful exploitation could lead to data breaches, system compromise, and denial of service conditions. The converter's role in document processing makes it a valuable target for attackers seeking to establish persistent access or exfiltrate sensitive information from enterprise networks. Organizations relying on this converter for document management, automation, or integration with other business systems face elevated risk of compromise, particularly in environments where document processing occurs without proper input sanitization.
Security mitigations for CVE-2018-3932 should focus on immediate patching of the affected converter version, as this represents the most effective defense against exploitation. Organizations should also implement network segmentation to limit access to the converter service and deploy intrusion detection systems to monitor for suspicious document conversion activities. Input validation measures should be strengthened at multiple levels, including implementing strict file format validation and size limitations for documents processed by the converter. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is classified under the broader category of buffer overflow conditions that can lead to arbitrary code execution. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution through application vulnerabilities, specifically targeting the execution of malicious code within the target system's memory space. Organizations should also consider implementing application whitelisting policies to restrict which applications can execute the converter, reducing the attack surface for exploitation attempts.