CVE-2025-59226 in Visio
Summary
by MITRE • 10/14/2025
Use after free in Microsoft Office Visio allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 10/25/2025
Microsoft Office Visio contains a use after free vulnerability that occurs when the application processes specially crafted Visio files. This flaw exists in the memory management handling of certain object references within the software's rendering engine. When a malicious Visio file is opened, the application attempts to free memory associated with a specific object while simultaneously allowing subsequent operations to reference that same memory location. This creates a scenario where an attacker can manipulate the freed memory to execute arbitrary code with the privileges of the current user. The vulnerability is particularly dangerous because it requires no special privileges to exploit, as the attack can be initiated through normal file opening procedures. The use after free condition falls under CWE-416 which specifically addresses the use of memory after it has been freed, making this a classic memory corruption vulnerability. According to ATT&CK framework, this vulnerability maps to T1059.007 for command and scripting interpreter and T1566.001 for spearphishing attachment, as the attack vector typically involves social engineering to deliver the malicious Visio file. The impact of successful exploitation includes potential system compromise, privilege escalation, and data exfiltration. Attackers can leverage this vulnerability to establish persistent access to victim systems, install backdoors, or perform lateral movement within networks. The vulnerability affects multiple versions of Microsoft Office Visio and represents a significant risk to organizations relying on Visio for diagramming and design work. The memory corruption aspect of this vulnerability makes it particularly challenging to detect and prevent, as the malicious code execution occurs during normal application usage patterns.
The technical implementation of this vulnerability involves the improper handling of COM objects within Visio's document processing pipeline. When a Visio file contains crafted malicious elements, the application's object lifecycle management fails to properly track references to freed memory blocks. This memory management flaw allows attackers to overwrite freed memory with malicious payloads, effectively hijacking the execution flow of the application. The vulnerability is triggered when Visio attempts to render specific diagram elements that contain malformed data structures, causing the application to free memory associated with those structures before all references are properly invalidated. The attacker can then manipulate the freed memory to contain shellcode or other malicious instructions that will execute when the application continues processing. This vulnerability demonstrates a critical flaw in the application's memory safety mechanisms and represents a failure in proper resource management practices. The use of memory after freeing creates an opportunity for attackers to perform code injection attacks, potentially leading to full system compromise. The exploitation requires minimal user interaction beyond opening the malicious file, making it particularly effective in phishing campaigns targeting office productivity environments.
Organizations should implement immediate mitigations to protect against this vulnerability, including updating to the latest Microsoft Office Visio patches and applying security updates from Microsoft. The recommended approach involves deploying the latest cumulative security updates and ensuring that all users have the most recent version of Visio installed. Network administrators should consider implementing application control policies that restrict the execution of Visio files from untrusted sources. Additionally, organizations should enhance their email filtering and endpoint protection solutions to detect and block malicious Visio attachments. Security monitoring should focus on detecting unusual Visio file processing activities and potential code execution attempts. The vulnerability's classification under CWE-416 emphasizes the need for proper memory management practices in software development, particularly in applications handling complex document formats. Organizations should also consider implementing principle of least privilege access controls and regularly auditing Visio file usage patterns within their environments. The attack surface for this vulnerability extends beyond individual user machines to include shared network resources where Visio files might be stored or accessed. Regular security awareness training for employees should emphasize the dangers of opening unknown Visio files and the importance of verifying file sources before opening attachments. System hardening measures including disabling unnecessary Visio features and implementing strict file type validation can further reduce the risk of exploitation. The vulnerability's impact on Microsoft Office Visio highlights the importance of maintaining current security patches and implementing layered defense strategies to protect against memory corruption vulnerabilities in productivity applications.