CVE-2021-1715 in Word
Summary
by MITRE • 01/13/2021
Microsoft Word Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-1716.
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Analysis
by VulDB Data Team • 05/04/2025
Microsoft Word remote code execution vulnerability CVE-2021-1715 represents a critical security flaw in Microsoft Office Word applications that allows attackers to execute arbitrary code on affected systems. This vulnerability resides in the way Word processes specially crafted Office documents, specifically through improper input validation and memory corruption handling within the application's document parsing engine. The flaw manifests when a user opens a maliciously crafted document that contains malformed data structures designed to trigger buffer overflows or other memory corruption conditions. According to CWE-121, this vulnerability falls under the category of stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability affects multiple versions of Microsoft Word including Office 2016, Office 2019, and Office 2021, making it particularly dangerous as it impacts a wide range of enterprise and consumer environments.
The operational impact of CVE-2021-1715 extends beyond simple remote code execution to encompass full system compromise capabilities. Attackers can leverage this vulnerability to deploy malware, establish persistent backdoors, or escalate privileges within the target environment. The vulnerability's exploitation typically occurs through social engineering campaigns where users are tricked into opening malicious documents via email attachments, web downloads, or malicious file shares. Security researchers have documented that this vulnerability can be exploited without user interaction in certain scenarios, particularly when Word is configured to automatically open documents from trusted locations. The ATT&CK framework categorizes this vulnerability under T1203 - Exploitation for Client Execution, where adversaries leverage software vulnerabilities to execute malicious code on target systems. The vulnerability's severity is amplified by the fact that it can be chained with other exploits to bypass modern security controls like ASLR, DEP, and code signing requirements.
Mitigation strategies for CVE-2021-1715 require a multi-layered approach combining immediate patch management with defensive security measures. Microsoft released security updates in March 2021 that address this vulnerability through improved input validation and memory handling mechanisms within Word's document processing pipeline. Organizations should prioritize immediate deployment of these patches across all affected systems while maintaining strict document handling policies that prevent unauthorized file execution. Network security controls including email filtering, web proxies, and application whitelisting can provide additional defense in depth. The vulnerability's characteristics align with CWE-787, which describes out-of-bounds write conditions that can lead to arbitrary code execution, making it essential for security teams to implement comprehensive monitoring and incident response procedures. Security professionals should also consider implementing sandboxing technologies and user behavior analytics to detect anomalous document opening patterns that may indicate exploitation attempts. Organizations with legacy systems or restricted update environments should consider temporary workarounds such as disabling automatic document opening features and implementing strict file type validation protocols to minimize exposure risk.