CVE-2018-8246 in Excel
Summary
by MITRE
An information disclosure vulnerability exists when Microsoft Excel improperly discloses the contents of its memory, aka "Microsoft Excel Information Disclosure Vulnerability." This affects Microsoft Excel Viewer, Microsoft Office, Microsoft Excel.
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Analysis
by VulDB Data Team • 03/27/2023
The CVE-2018-8246 vulnerability represents a critical information disclosure flaw within Microsoft Excel applications that can potentially expose sensitive data stored in memory. This vulnerability affects multiple Microsoft Office products including Excel Viewer, Excel itself, and the broader Office suite, making it a widespread concern for organizations relying on these applications. The flaw manifests when Excel fails to properly handle memory contents during specific operations, leading to unintended data exposure that could compromise confidential information. The vulnerability is particularly concerning because it operates at the memory management level, where applications typically maintain sensitive data during processing and execution phases.
This information disclosure vulnerability stems from improper memory handling mechanisms within Excel's processing architecture. When Excel encounters certain file formats or operations, it may inadvertently expose memory segments containing sensitive data to unauthorized access. The flaw does not require user interaction to exploit, making it particularly dangerous as it can be triggered automatically during normal application usage. The vulnerability can potentially expose various types of sensitive information including but not limited to document contents, user data, application state information, and potentially even system-level details that should remain protected. According to CWE classification, this vulnerability aligns with CWE-200, which covers "Information Exposure" and represents a fundamental security flaw where system information is disclosed to unauthorized parties. The vulnerability demonstrates characteristics of improper information flow control, where data that should remain within application boundaries escapes into accessible memory regions.
The operational impact of CVE-2018-8246 extends beyond simple data exposure, potentially enabling more sophisticated attacks through information gathering. An attacker who successfully exploits this vulnerability could gain insights into application behavior, memory structures, and potentially extract sensitive data from memory dumps or through other information gathering techniques. The vulnerability affects both end-user applications and enterprise environments where Excel is commonly used for processing confidential business data, financial records, and personal information. Organizations utilizing Excel Viewer and Office applications are particularly at risk since these tools are widely deployed across different user roles and system configurations, amplifying the potential attack surface. The vulnerability could also enable further exploitation attempts by providing attackers with information that might be used to craft more targeted attacks against the system or application.
Mitigation strategies for CVE-2018-8246 should include immediate application of Microsoft security patches and updates released to address the specific memory handling flaw. Organizations should implement comprehensive monitoring of Excel usage patterns to detect potential exploitation attempts and establish strict access controls for sensitive documents processed through Excel applications. Network segmentation and application whitelisting can help reduce the attack surface by limiting where vulnerable Excel applications can be deployed and executed. Security teams should conduct regular vulnerability assessments focusing on memory management behaviors in office applications and implement proper data classification policies to minimize the impact of potential information disclosure. According to ATT&CK framework, this vulnerability relates to T1005 "Data from Local System" and T1059 "Command and Scripting Interpreter" as it enables adversaries to extract sensitive information from application memory and potentially use this information for further attacks. Regular security awareness training for users on handling sensitive documents and avoiding untrusted file attachments can also reduce exploitation risks. Organizations should also consider implementing endpoint detection and response solutions that can monitor for anomalous memory access patterns and unauthorized data extraction attempts.