CVE-2020-1503 in Word
Summary
by MITRE
An information disclosure vulnerability exists when Microsoft Word improperly discloses the contents of its memory. An attacker who exploited the vulnerability could use the information to compromise the user’s computer or data. To exploit the vulnerability, an attacker could craft a special document file and then convince the user to open it. An attacker must know the memory address location where the object was created. The update addresses the vulnerability by changing the way certain Word functions handle objects in memory.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability identified as CVE-2020-1503 represents a critical information disclosure flaw within Microsoft Word that stems from improper memory handling mechanisms. This weakness allows attackers to potentially extract sensitive data from the application's memory space, creating a significant security risk for users who may inadvertently open maliciously crafted documents. The vulnerability specifically affects how Word processes and manages objects within its memory structure, creating an opportunity for adversaries to gain unauthorized access to potentially sensitive information that should remain protected within the application's secure memory boundaries.
The technical exploitation of this vulnerability requires a sophisticated approach that involves crafting specially designed document files to trigger the memory disclosure behavior. Attackers must possess knowledge of specific memory address locations where objects were created within Word's memory space to effectively exploit the flaw. This requirement demonstrates that the vulnerability operates at a low-level memory management interface, where the application fails to properly isolate or protect certain memory regions containing sensitive data structures or information. The attack vector relies on social engineering elements to convince victims to open the malicious documents, making it particularly dangerous in enterprise environments where users may encounter such files through email attachments or shared network resources.
The operational impact of CVE-2020-1503 extends beyond simple data exposure, as the leaked memory contents could potentially contain session tokens, encryption keys, user credentials, or other sensitive information that could be leveraged for further attacks. This information disclosure could enable attackers to perform privilege escalation, maintain persistent access to compromised systems, or conduct more sophisticated attacks such as credential theft or lateral movement within network environments. The vulnerability's potential to compromise user computers and data makes it particularly concerning for organizations that rely heavily on Microsoft Office applications for business operations, as it could serve as a gateway for more extensive security breaches.
Microsoft addressed this vulnerability through targeted updates that modify the memory handling mechanisms of specific Word functions, particularly those related to object management and memory allocation. The fix involves changes to how Word processes and manages objects within its memory space to prevent unauthorized information disclosure. This remediation aligns with security best practices for memory safety and follows established frameworks such as the CWE-200 principle of information exposure, which emphasizes the importance of protecting sensitive information from unauthorized access. The update represents a defensive programming approach that ensures proper memory isolation and access controls, preventing the leakage of sensitive data through improper memory management practices. Organizations should prioritize applying these security updates to protect against potential exploitation attempts and maintain the integrity of their document processing environments.