CVE-2010-3234 in Excel
Summary
by MITRE
Microsoft Excel 2002 SP3 does not properly validate formula information, which allows remote attackers to execute arbitrary code via a crafted Excel document, aka "Formula Substream Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 09/26/2021
The vulnerability identified as CVE-2010-3234 represents a critical memory corruption flaw in Microsoft Excel 2002 Service Pack 3 that stems from inadequate validation of formula information within Excel document structures. This vulnerability specifically affects the handling of formula substreams during document processing, creating a pathway for remote code execution attacks. The flaw exists in the way Excel parses and processes formula data within workbook files, particularly when encountering malformed or specially crafted formula substream structures that exceed expected memory boundaries or violate internal validation checks.
This vulnerability operates through a classic buffer overflow mechanism where maliciously constructed Excel documents contain formula data that triggers improper memory handling during the parsing process. When Excel attempts to process these crafted formula substreams, the application fails to properly validate the size and structure of the formula data, leading to memory corruption that can be exploited to execute arbitrary code with the privileges of the targeted user. The vulnerability is particularly dangerous because it can be triggered through simple file opening operations, making it an attractive target for phishing campaigns and malicious file distribution.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data theft. Attackers can leverage this flaw to gain unauthorized access to systems running vulnerable Excel versions, potentially escalating privileges and establishing persistent access. The vulnerability affects enterprise environments where Excel documents are frequently shared and opened, creating numerous attack vectors through email attachments, file downloads, and collaborative document sharing. Organizations with limited security awareness training are particularly vulnerable as users may unknowingly open malicious documents that trigger the exploit.
Microsoft addressed this vulnerability through security updates that improved formula substream validation and memory handling within Excel's document processing engine. The fix implemented stricter bounds checking and input validation for formula data structures, preventing the memory corruption that enabled arbitrary code execution. Security professionals should note that this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and demonstrates characteristics consistent with ATT&CK technique T1059.005 for command and scripting interpreter execution. Organizations should prioritize patch management and implement additional security controls such as email filtering, application whitelisting, and user education to mitigate risks associated with this and similar vulnerabilities. The vulnerability also highlights the importance of maintaining current security patches and understanding the attack surface presented by office productivity applications that handle external data inputs.