CVE-2025-53784 in Word
Summary
by MITRE • 08/12/2025
Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/19/2025
The vulnerability identified as CVE-2025-53784 represents a critical use after free flaw within Microsoft Office Word applications that enables remote code execution under specific conditions. This vulnerability arises from improper memory management practices where the application continues to reference memory locations after they have been freed, creating potential exploitation opportunities for malicious actors. The flaw exists in the document processing engine responsible for handling various file formats and internal structures within word processing documents. Attackers can leverage this vulnerability by crafting malicious documents that trigger the flawed memory management sequence during document parsing or rendering operations, ultimately allowing them to execute arbitrary code with the privileges of the targeted user. The vulnerability demonstrates characteristics consistent with CWE-416, which specifically addresses use after free conditions in software implementations. This type of vulnerability falls under the ATT&CK technique T1059.001 for command and script interpreter, as successful exploitation would enable attackers to execute code within the target system's context. The exploitation requires a user to open a specially crafted malicious document, making social engineering and user interaction critical components of the attack vector. The vulnerability affects multiple versions of Microsoft Office Word, particularly those that process complex document structures including embedded objects, macros, and formatting elements that could trigger the memory corruption state.
The technical implementation of this vulnerability involves the application's failure to properly validate memory references after deallocation operations within the document processing pipeline. When Word encounters specific document elements, particularly those involving complex formatting or embedded content, it may prematurely free memory structures while still maintaining pointers to those locations. This creates a scenario where subsequent memory access operations can overwrite or corrupt data in ways that allow attackers to inject and execute malicious code. The flaw typically manifests during document rendering or parsing phases where the application processes embedded objects, table structures, or formatting elements that require dynamic memory allocation and deallocation. The exploitation process involves carefully crafting document content that triggers the specific memory management path leading to the use after free condition. Attackers often utilize techniques such as heap spraying or memory layout manipulation to ensure successful code execution within the target process. The vulnerability is particularly concerning because it operates at the application level without requiring administrative privileges, making it a prime target for targeted attacks against end-user systems. The memory corruption occurs in a manner that can be reliably reproduced under controlled conditions, making this vulnerability suitable for exploitation in real-world scenarios.
The operational impact of CVE-2025-53784 extends beyond simple local privilege escalation, as successful exploitation provides attackers with complete control over the affected system. The vulnerability enables a range of malicious activities including data exfiltration, system reconnaissance, persistence establishment, and lateral movement within network environments. Attackers can leverage this vulnerability to install backdoors, deploy additional malware payloads, or establish command and control communications without detection. The local code execution capability means that attackers can perform actions that would normally require elevated privileges, potentially allowing them to access sensitive files, modify system configurations, or compromise other network resources. The vulnerability's exploitation requires minimal user interaction beyond opening the malicious document, making it particularly dangerous in corporate or enterprise environments where users frequently open documents from external sources. Organizations that rely heavily on Microsoft Office Word for document processing are at significant risk, especially those with less robust security controls or limited user education about phishing attacks. The vulnerability can be exploited through various document formats including .doc, .docx, and other Word-compatible formats that support complex document structures. Security researchers have identified that the vulnerability can be triggered through multiple document processing pathways, increasing the attack surface and making comprehensive protection more challenging.
Mitigation strategies for CVE-2025-53784 should encompass both immediate defensive measures and long-term security improvements. Microsoft has released security updates addressing this vulnerability through regular security patches, which should be applied immediately to all affected systems. Organizations should implement strict document filtering policies that restrict the opening of documents from untrusted sources and disable macro execution by default. Network-based security controls including email filtering, web proxies, and endpoint detection systems can help prevent malicious documents from reaching end users. User education and awareness programs should emphasize the dangers of opening unexpected documents and the importance of verifying document sources before processing. Security teams should monitor for indicators of compromise related to this vulnerability and implement behavioral analysis to detect anomalous code execution patterns. The implementation of application whitelisting can prevent execution of unauthorized code even if exploitation occurs. Regular vulnerability assessments and penetration testing should be conducted to identify potential exploitation paths and ensure that mitigation measures remain effective. Additional defensive measures include disabling unnecessary Office features, implementing strict macro security policies, and maintaining up-to-date antivirus signatures that can detect malicious document content. Organizations should also consider implementing network segmentation to limit the potential impact of successful exploitation and establish incident response procedures specifically addressing this vulnerability type. The vulnerability's characteristics make it particularly suitable for targeted attacks, so organizations should focus on protecting high-value targets and implementing layered security controls to reduce the probability of successful exploitation.