CVE-2020-1483 in Office
Summary
by MITRE
A remote code execution vulnerability exists in Microsoft Outlook when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Outlook software. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file. Note that where severity is indicated as Critical in the Affected Products table, the Preview Pane is an attack vector. The security update addresses the vulnerability by correcting how Outlook handles objects in memory.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability described in CVE-2020-1483 represents a critical remote code execution flaw in Microsoft Outlook software that stems from improper handling of objects in memory. This type of vulnerability falls under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read conditions where software fails to properly validate memory access boundaries. The flaw exists in the memory management mechanisms of Outlook, allowing attackers to manipulate how the application processes certain file objects, potentially leading to arbitrary code execution. The vulnerability is particularly concerning because it operates at the memory level, where attackers can exploit the application's failure to properly validate or sanitize memory operations, creating a pathway for privilege escalation attacks.
The operational impact of this vulnerability extends beyond simple code execution to full system compromise when users operate with administrative privileges. According to the ATT&CK framework, this vulnerability maps to multiple techniques including T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation. When exploited successfully, the vulnerability allows attackers to execute code with the privileges of the current user, which can escalate to system-level control if the user account has administrative rights. The attack vector requires user interaction through opening a specially crafted file, making it a classic example of a user-initiated attack that leverages social engineering elements. This approach aligns with ATT&CK technique T1566 for social engineering, where attackers manipulate users into performing actions that compromise security.
The exploitation methodology involves crafting malicious files that trigger the memory handling flaw when opened by Outlook. In email-based attacks, attackers would send these files as attachments, relying on users to open them without proper security awareness. Web-based exploitation requires hosting malicious content that users might encounter through links in emails or instant messages, with the attacker needing to convince users to click through to the malicious content and subsequently open the file. This attack model demonstrates how the vulnerability can be leveraged through multiple vectors, making it particularly dangerous for organizations. The security update addresses this by implementing proper memory handling procedures that validate object boundaries and prevent out-of-bounds memory access that would otherwise allow arbitrary code execution.
Organizations must understand that this vulnerability creates a significant risk when users have administrative privileges, as the potential for complete system compromise increases dramatically. The memory-based nature of the flaw means that traditional network-based security controls may not prevent exploitation, since the attack occurs within the application's memory space. Security teams should implement comprehensive user education programs to reduce the risk of successful exploitation, as the vulnerability requires user interaction to be effective. The fix provided by Microsoft addresses the root cause by improving memory management practices and ensuring proper validation of objects before processing them, which helps prevent the out-of-bounds memory access that enables the remote code execution capability. This remediation approach aligns with secure coding practices that emphasize proper input validation and memory boundary checking to prevent similar vulnerabilities from occurring in the future.