CVE-2013-3856 in Office
Summary
by MITRE
Microsoft Word 2003 SP3 and Word Viewer allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted Office document, aka "Word Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 05/24/2021
The CVE-2013-3856 vulnerability represents a critical memory corruption flaw in Microsoft Word 2003 Service Pack 3 and Word Viewer applications. This vulnerability stems from improper handling of malformed Office document structures during the parsing process, creating a condition where maliciously crafted documents can trigger unexpected memory behavior. The flaw exists within the document processing engine that fails to properly validate input data structures, particularly when encountering specially constructed Office files designed to exploit buffer overflows or other memory management issues. Security researchers have classified this as a remote code execution vulnerability due to its ability to allow attackers to execute arbitrary code on vulnerable systems without requiring local access or user interaction beyond opening the malicious document.
The technical implementation of this vulnerability involves manipulation of Office document format elements that are processed during document rendering or parsing operations. When Word attempts to parse a crafted document containing malformed data structures, the application's memory management routines fail to properly handle the unexpected input, leading to memory corruption that can be leveraged by attackers. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes heap-based buffer overflow conditions, and more specifically aligns with CWE-125, representing out-of-bounds read vulnerabilities. The vulnerability's exploitation pathway follows the ATT&CK framework's technique T1059.005, which covers command and scripting interpreter usage, as successful exploitation typically involves execution of malicious code through the compromised application's process.
The operational impact of this vulnerability extends beyond simple remote code execution to include potential denial of service conditions that can crash the affected Word application or even the entire system. Attackers can craft documents that trigger memory corruption in such a way that they either cause the application to crash repeatedly or allow for more sophisticated exploitation techniques that can escalate privileges and establish persistent access. The vulnerability affects a wide range of Microsoft Office products including Word 2003 SP3 and Word Viewer, making it particularly dangerous as these applications are commonly found in enterprise environments and are frequently used for document sharing. The lack of user interaction requirements for exploitation makes this vulnerability particularly concerning for organizations that regularly process external documents or have less strict email filtering policies.
Organizations should prioritize immediate mitigation through Microsoft's security patches and updates, as the vulnerability has been addressed through official security releases. System administrators should implement comprehensive email filtering solutions that can detect and block potentially malicious Office documents, particularly those with unusual file extensions or embedded malicious content. Network segmentation and application whitelisting can provide additional defense layers to prevent unauthorized execution of vulnerable applications. The vulnerability also highlights the importance of maintaining up-to-date security patches across all Microsoft Office installations, as older versions remain susceptible to exploitation. Security monitoring should include detection of unusual Word process behavior or memory allocation patterns that could indicate exploitation attempts. Organizations should also consider implementing sandboxing techniques for document processing and conducting regular security assessments to identify and remediate similar vulnerabilities in their software environments.