CVE-2011-1990

Microsoft Excel 2007 Service Pack 2; Excel en Office 2007 SP2, Excel Viewer SP2, Paquete de compatibilidad de Office para Word, Excel y PowerPoint 2007 Service Pack 2, y Servicios de Excel en Office SharePoint Server 2007 SP2 no validan correctamente el signo de un índice no especificado de una matriz, lo que permite ejecutar código de su elección a atacantes remotos a través de una hoja de cálculo debidamente modificada. Es un problema también conocido como "Vulnerabilidad de indexación de matrices fuera de límites".

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Office 2007. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the implementation of a record inside a Microsoft Office Excel or PowerPoint document. When parsing a signed field from this structure, the application will use the field to seek into an array of objects. Due to this unbounded index, an attacker can cause an element outside the array to be treated as a different type. This type of corruption can lead to code execution under the context of the application.