With the constant growth and evolution of digital space, cybersecurity continues to be a major concern for organizations and individuals across the globe. The Windows operating system, which is widely used in a variety of systems, requires constant patching and updates to ensure the safety and security of its users. In this post, we will discuss a recent vulnerability found in the Windows NTFS (New Technology File System) - CVE-2025-27483, which allows a local attacker to exploit the system and elevate their privileges, gaining unauthorized access to sensitive information.

Vulnerability Overview

CVE-2025-27483 is an out-of-bounds read vulnerability in Windows NTFS which affects Windows 10, Windows Server 2016, and Windows Server 2019 operating systems. An out-of-bounds read occurs when a program reads data from a buffer which is outside its boundary, leading to incorrect or unintended data being read. This could potentially be exploited by an attacker to manipulate the program's execution and gain unauthorized access to privileged information. In this case, the vulnerability exists in the way NTFS handles certain file operations, allowing the attacker to exploit it and elevate their privileges locally.

Exploit Details

To understand this vulnerability in detail, let us examine the following code snippet, which represents a portion of the NTFS code involved in handling file operations.

void vulnerable_function()
{
    USHORT RequestedFileLength;
    // ... some code ...
    char Buffer[1024];
    // ... some more code ...
    memcpy(Buffer, RequestedFileLength);
    // ... rest of the code ...
}

In this code snippet, the variable RequestedFileLength is supposed to represent the size of a file that the user wants to read. However, due to the lack of proper validation checks, an attacker can provide an arbitrary value for RequestedFileLength, causing the memcpy function to read data beyond the buffer's boundaries. This results in the out-of-bounds read vulnerability in the NTFS system.

The attacker, who is already authenticated on the affected system, can craft a malicious application that exploits this vulnerability and thereby gain elevated access rights. Once the exploit is successful, the attacker can modify, delete or add data to the system, which could have catastrophic consequences depending on the sensitivity of the data.

For an in-depth technical analysis of this vulnerability, refer to the following resources

- Mitre CVE Details - CVE-2025-27483
- Microsoft Security Advisory - CVE-2025-27483
- National Vulnerability Database - CVE-2025-27483

Mitigation and Recommendations

Microsoft has acknowledged this vulnerability and has already released security updates to address and patch the issue. Affected users should immediately install these updates to ensure their systems' protection from potential exploitation. Additionally, it is recommended that users follow proper access controls management practices, including:

Limiting local users' privileges to the least necessary for their tasks.

2. Granting administrative access only when required, and monitoring the usage of administrative privileges.

Conclusion

Out-of-bounds read vulnerabilities like CVE-2025-27483 are a constant threat to the cybersecurity landscape. Timely identification and patching of such vulnerabilities can help protect systems and data from potential exploitation. Users need to remain vigilant and keep their systems updated, employ robust security practices, and maintain proper access controls to minimize the risks associated with cybersecurity threats.

Timeline

Published on: 04/08/2025 18:15:58 UTC
Last modified on: 05/06/2025 17:03:38 UTC