CVE-2017-8501 in Office
Summary
by MITRE
Microsoft Office allows a remote code execution vulnerability due to the way that it handles objects in memory, aka "Microsoft Office Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8502.
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Analysis
by VulDB Data Team • 12/31/2020
The vulnerability identified as CVE-2017-8501 represents a critical memory corruption flaw within Microsoft Office applications that enables remote code execution under specific conditions. This vulnerability specifically affects how Microsoft Office processes objects in memory, creating a pathway for malicious actors to exploit the software's handling of memory structures. The flaw manifests when Office applications encounter specially crafted malicious files or documents that trigger improper memory management during object processing, leading to potential arbitrary code execution on affected systems. The vulnerability is particularly concerning because it can be triggered through various attack vectors including email attachments, web downloads, or malicious documents opened within the Office environment. Security researchers have classified this as a remote code execution vulnerability due to its ability to allow attackers to execute malicious code on target systems without requiring local access or user interaction beyond opening a malicious document.
The technical root cause of CVE-2017-8501 stems from improper memory handling within Microsoft Office's object model processing mechanisms. When Office applications encounter malformed or maliciously constructed objects in memory, the software fails to properly validate or sanitize these structures before processing them. This memory corruption occurs during the parsing and rendering of Office document formats, particularly affecting components that handle complex object relationships and memory allocation patterns. The vulnerability is categorized under CWE-125: "Out-of-bounds Read" and CWE-787: "Out-of-bounds Write" within the Common Weakness Enumeration framework, indicating that the flaw involves reading or writing beyond the boundaries of allocated memory regions. Attackers can exploit this by crafting malicious documents that cause Office to access invalid memory locations, potentially leading to memory corruption that can be leveraged for code execution. The vulnerability is further classified under the ATT&CK framework as a technique for "Exploitation for Client Execution" under the T1203 category, demonstrating how adversaries can use memory corruption vulnerabilities to gain remote code execution capabilities on target systems.
The operational impact of CVE-2017-8501 extends significantly across enterprise environments where Microsoft Office is widely deployed, as the vulnerability can be exploited through multiple attack vectors that do not require sophisticated targeting or specialized knowledge. Organizations running affected versions of Microsoft Office are at risk of unauthorized access, data breaches, and potential complete system compromise when users open malicious documents. The vulnerability's remote execution capability means that attackers can exploit systems from outside the network perimeter, making it particularly dangerous for organizations with limited network segmentation or insufficient email filtering controls. The attack surface is broad since the vulnerability affects common Office file formats including doc, docx, xls, xlsx, ppt, and pptx, making it difficult for organizations to protect against all potential attack vectors. Additionally, the vulnerability's exploitation can bypass many traditional security controls since it operates within the legitimate Office application context, making detection more challenging for security monitoring systems.
Mitigation strategies for CVE-2017-8501 should encompass multiple layers of defense to protect against exploitation attempts. Microsoft released security updates and patches for affected Office versions, including cumulative updates that address the memory corruption vulnerability. Organizations should prioritize immediate deployment of these security patches, particularly for systems that process external documents or receive email attachments from untrusted sources. Network-based protections should include email filtering solutions that can detect and quarantine malicious Office documents, along with web application firewalls that can block access to known malicious domains. Endpoint protection measures should be enhanced with behavior monitoring tools that can detect anomalous memory access patterns or suspicious code execution attempts. Security configuration hardening should include disabling automatic opening of Office documents from email attachments, implementing strict file type restrictions, and limiting user privileges to reduce the potential impact of successful exploitation. Additional protective measures include regular security awareness training for users to recognize potential social engineering attempts, implementation of network segmentation to limit lateral movement, and maintaining comprehensive backup strategies to ensure rapid recovery in case of successful exploitation. The vulnerability also highlights the importance of regular vulnerability assessments and penetration testing to identify similar memory corruption issues in other applications within the organization's attack surface.