CVE-2016-3363 in Office
Summary
by MITRE
Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Excel 2016, Office Compatibility Pack SP3, and Excel Viewer allow remote attackers to execute arbitrary code via a crafted document, aka "Microsoft Office Memory Corruption Vulnerability," a different vulnerability than CVE-2016-3381.
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Analysis
by VulDB Data Team • 09/16/2022
This vulnerability represents a critical memory corruption flaw in Microsoft Excel software versions spanning multiple product lines including Excel 2007 through Excel 2016 along with the Office Compatibility Pack and Excel Viewer. The vulnerability falls under the category of remote code execution exploits that can be triggered through maliciously crafted Excel documents, making it particularly dangerous in enterprise environments where users frequently open documents from untrusted sources. The flaw enables attackers to execute arbitrary code on affected systems with the privileges of the logged-on user, potentially leading to complete system compromise and data exfiltration.
The technical nature of this vulnerability stems from improper handling of memory operations within Excel's document parsing engine when processing specially crafted spreadsheet files. Attackers can construct malicious documents that, when opened by an affected Excel version, cause the application to improperly manage memory allocation and deallocation, resulting in memory corruption that can be leveraged to inject and execute malicious code. This type of vulnerability typically involves buffer overflows, use-after-free conditions, or other memory management errors that allow attackers to overwrite critical memory locations. The vulnerability is classified as a memory corruption issue that aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations.
The operational impact of this vulnerability extends beyond simple code execution to encompass significant security implications for organizations relying on Microsoft Office suites. Attackers can exploit this vulnerability to establish persistent backdoors, escalate privileges, and move laterally within networks without requiring user interaction beyond opening the malicious document. This makes the vulnerability particularly dangerous in targeted attacks where adversaries seek to maintain long-term access to compromised systems. The attack surface is broad since the vulnerability affects multiple Excel versions and can be delivered through various vectors including email attachments, web downloads, and malicious documents shared through collaboration platforms. Organizations may experience unauthorized data access, system compromise, and potential regulatory compliance violations when such vulnerabilities are exploited.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security patches and updates, which address the underlying memory corruption issues in Excel's document processing components. Network segmentation and email filtering solutions should be implemented to prevent users from accessing potentially malicious documents, while user education programs should emphasize the importance of not opening unexpected attachments. Security monitoring should focus on unusual Excel process behavior and memory allocation patterns that might indicate exploitation attempts. The vulnerability also aligns with ATT&CK technique T1203, which covers exploitation for client execution through malicious documents, and T1059, which covers command and scripting interpreter usage. Organizations should implement least privilege access controls and regularly audit Excel-related processes to detect potential exploitation attempts. Additionally, the use of application whitelisting and exploit prevention tools can provide additional layers of defense against this type of memory corruption attack.