CVE-2011-1983 in Word
Summary
by MITRE
Use-after-free vulnerability in Microsoft Office 2007 SP2 and SP3, Office 2010 Gold and SP1, and Office for Mac 2011 allows remote attackers to execute arbitrary code via a crafted Word document, aka "Word Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 01/12/2025
The CVE-2011-1983 vulnerability represents a critical use-after-free flaw in Microsoft Office applications that affects multiple versions including Office 2007 SP2 and SP3, Office 2010 Gold and SP1, and Office for Mac 2011. This vulnerability falls under the CWE-416 category of Use After Free, which occurs when a program continues to reference memory after it has been freed, creating opportunities for malicious code execution. The flaw specifically manifests in the Word processing engine where improper memory management allows attackers to manipulate freed memory regions through carefully crafted malicious documents.
The technical implementation of this vulnerability involves the exploitation of memory allocation patterns within Microsoft Office's document parsing mechanisms. When processing malformed Word documents, the application fails to properly validate memory references, leading to a scenario where freed memory blocks are accessed again by subsequent operations. This memory corruption can be leveraged by attackers to overwrite critical program structures or inject malicious code into the application's execution context. The vulnerability is particularly dangerous because it can be triggered through email attachments or web downloads, making it suitable for remote code execution attacks.
From an operational perspective, this vulnerability presents significant risk to enterprise environments where Microsoft Office is widely deployed. Attackers can craft malicious Word documents that, when opened by unsuspecting users, trigger the use-after-free condition and execute arbitrary code with the privileges of the compromised user. The attack surface is extensive given that Word documents are commonly shared through email, file sharing systems, and web downloads, making this vulnerability particularly effective for mass exploitation campaigns. The remote execution capability means that attackers do not require physical access to target systems, enabling large-scale attacks against organizations.
The impact of CVE-2011-1983 aligns with ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code on target systems. This vulnerability also maps to the broader ATT&CK tactic of Execution, as successful exploitation results in arbitrary code execution. Organizations should implement multiple layers of defense including regular security updates, email filtering solutions, and user education programs to mitigate the risk. The vulnerability demonstrates the importance of maintaining up-to-date software patches and highlights the critical nature of memory safety in application development. Security professionals should monitor for indicators of compromise related to malicious document delivery and implement network-based detection measures to identify potential exploitation attempts.
Microsoft addressed this vulnerability through security updates that corrected the memory management issues in the affected Office versions. The vulnerability serves as a prime example of why automated patch management systems are essential for maintaining organizational security posture. Organizations that failed to apply the relevant security updates remained vulnerable to exploitation by threat actors who actively targeted this specific flaw in their attack campaigns. The remediation process required careful deployment planning due to the widespread use of these Office versions in enterprise environments, making the vulnerability particularly challenging to secure across large organizations.