CVE-2012-1885 in Office Excel
Summary
by MITRE
Heap-based buffer overflow in Microsoft Excel 2003 SP3, 2007 SP2 and SP3, and 2010 SP1; Office 2008 and 2011 for Mac; and Office Compatibility Pack SP2 and SP3 allows remote attackers to execute arbitrary code via a crafted spreadsheet, aka "Excel SerAuxErrBar Heap Overflow Vulnerability."
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/19/2021
This vulnerability represents a critical heap-based buffer overflow flaw in Microsoft Excel's handling of spreadsheet files, specifically affecting versions including Excel 2003 SP3, 2007 SP2 and SP3, 2010 SP1, Office 2008 and 2011 for Mac, and the Office Compatibility Pack SP2 and SP3. The vulnerability stems from improper input validation when processing certain spreadsheet elements, creating conditions where maliciously crafted spreadsheet files can trigger memory corruption. The flaw is categorized under CWE-121 Heap-based Buffer Overflow, which occurs when a program writes data beyond the boundaries of a heap-allocated buffer, potentially allowing attackers to overwrite adjacent memory locations and execute arbitrary code. The vulnerability is particularly dangerous because it can be exploited through social engineering attacks where users open maliciously crafted spreadsheet files, making it a prime target for targeted attacks.
The technical exploitation of this vulnerability involves the manipulation of spreadsheet elements that are processed by Excel's internal SerAuxErrBar functionality, which handles error bar data in charts. When Excel encounters a specially crafted spreadsheet file with malformed data structures, it fails to properly validate buffer boundaries during memory allocation and data copying operations. This allows attackers to overwrite heap memory with controlled data, potentially leading to code execution with the privileges of the user running Excel. The vulnerability is particularly concerning because it can be triggered remotely through email attachments, web downloads, or shared network drives, making it an attractive vector for widespread exploitation. Attackers can leverage this vulnerability to execute malicious code on targeted systems, potentially establishing persistence, exfiltrating data, or escalating privileges within the compromised environment.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to perform various malicious activities including privilege escalation, data theft, and system compromise. Organizations using affected Excel versions face significant risk from targeted attacks, especially those with limited security awareness training or outdated patch management processes. The vulnerability's exploitation does not require user interaction beyond opening the malicious file, making it particularly dangerous in enterprise environments where users may inadvertently open compromised attachments. Security professionals should note that this vulnerability aligns with ATT&CK technique T1059.005 for command and scripting interpreter, and T1068 for exploit for privilege escalation, as attackers can use the initial code execution to gain broader system access.
Mitigation strategies for this vulnerability primarily focus on immediate patch deployment and operational security measures. Microsoft released security updates addressing this vulnerability through their regular patching cycle, and organizations should prioritize applying these patches across all affected systems. Additional mitigations include implementing email filtering rules to block suspicious spreadsheet attachments, disabling automatic execution of macros in Excel, and employing sandboxing technologies for processing untrusted files. Network segmentation and monitoring for unusual file access patterns can help detect potential exploitation attempts. Security teams should also consider implementing application whitelisting policies that restrict execution of unauthorized Office applications and maintain comprehensive incident response procedures for handling potential exploitation events. The vulnerability demonstrates the importance of maintaining current security patches and highlights the need for robust application hardening practices in enterprise environments.