CVE-2015-2376 in Excel
Summary
by MITRE
Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Office for Mac 2011, Excel Viewer 2007 SP3, Office Compatibility Pack SP3, Excel Services on SharePoint Server 2007 SP3, Excel Services on SharePoint Server 2010 SP2, and Excel Services on SharePoint Server 2013 SP1 allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted Office document, aka "Microsoft Office Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 05/31/2022
The vulnerability identified as CVE-2015-2376 represents a critical memory corruption flaw affecting multiple versions of Microsoft Excel and related Office components. This vulnerability resides within the way these applications process specially crafted Office documents, particularly those containing maliciously constructed data structures that trigger buffer overflows or heap corruption during document parsing operations. The flaw manifests when Excel attempts to parse malformed or specially crafted spreadsheet files, leading to unpredictable behavior that can be exploited by remote attackers to gain unauthorized system access or cause system instability.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read vulnerabilities. These classifications indicate that the flaw occurs during memory allocation and manipulation processes within Excel's document parsing engine. The vulnerability can be exploited through various attack vectors including email attachments, web downloads, or malicious Office documents hosted on compromised websites. When a user opens a maliciously crafted Excel file, the application's memory management routines fail to properly validate input data, resulting in memory corruption that can be leveraged to execute arbitrary code with the privileges of the logged-in user.
From an operational perspective, this vulnerability presents significant risk to enterprise environments where users frequently open Office documents from external sources or untrusted networks. The attack requires minimal user interaction beyond opening a malicious document, making it particularly dangerous in targeted phishing campaigns or social engineering attacks. The potential impact includes complete system compromise, data exfiltration, privilege escalation, and persistent backdoor installation. Additionally, the vulnerability can cause denial of service conditions that may disrupt business operations, particularly in environments where Excel Services on SharePoint servers are utilized for document processing and collaboration.
Organizations should implement multiple layers of defense to mitigate this vulnerability, including immediate deployment of Microsoft security updates and patches released through Windows Update or Microsoft Update Catalog. Network segmentation and email filtering solutions should be configured to block suspicious Office document attachments, while user education programs should emphasize the importance of verifying document sources before opening. Security monitoring should focus on detecting anomalous Excel process behavior, unusual memory consumption patterns, and network connections initiated by Office applications. The ATT&CK framework categorizes this vulnerability under T1203, which covers "Exploitation for Client Execution," and T1059, which covers "Command and Scripting Interpreter," indicating that exploitation typically involves leveraging compromised systems to execute malicious payloads through command-line interfaces or scripting languages. Organizations should also consider implementing application whitelisting policies to restrict execution of unauthorized Office applications and maintain regular vulnerability assessments to identify similar memory corruption issues in other Microsoft Office components and third-party applications.