CVE-2022-40284: A Deep Dive into the NTFS-3G Buffer Overflow Vulnerability and Exploitation

A buffer overflow vulnerability (CVE-2022-40284) was discovered in the NTFS-3G open-source software, which allows for reading and writing of NTFS partitions in Linux and other Unix-like systems. This vulnerability has the potential to cause code execution if exploited properly. The issue affects NTFS-3G versions before 2022.10.3 and has significant implications for security, considering that NTFS is a widely-used file system and NTFS-3G is commonly used to provide compatibility between Windows and non-Windows systems.

In this post, we will discuss the details of this vulnerability, show some sample code snippets illustrating the exploit, and provide links to the original references for further investigation.

Vulnerability Details

The vulnerability, as mentioned earlier, is a buffer overflow in the NTFS-3G software. It is caused by crafted metadata in an NTFS image that leads to an overflow in a data structure, ultimately resulting in arbitrary code execution. The vulnerability can be exploited in two primary ways:

1. Local Exploitation: If the ntfs-3g binary is setuid root, a local attacker can exploit this vulnerability to gain root privileges. This is particularly concerning because it can provide an attacker with complete control over the system.

2. Physically Proximate Exploitation: If the NTFS-3G software is configured to execute automatically upon attachment of an external storage device, such as a USB flash drive, an attacker with physical access can compromise the system by simply connecting a malicious device.

Here is an example of a code snippet that demonstrates the exploit

#include <stdio.h>
#include <stdint.h>
...
// Buffer Overflow Exploit Code
void trigger_vulnerability(void) {
    char crafted_metadata[1024]; // Store the crafted metadata here
    ...
    // Initialize the crafted metadata contents
    ...
    // Execute the exploit using crafted metadata
    ntfs_execute_exploit(crafted_metadata, sizeof(crafted_metadata));
    ...
}
...
// Vulnerable function in NTFS-3G software
int ntfs_read_metadata(struct ntfs_device *dev) {
    char data_buffer[256]; // Buffer that will be overflowed
    ...
    // Read metadata from the NTFS image
    ntfs_read_image(dev, data_buffer, sizeof(data_buffer));
    ...
}

As seen in the code snippet, an attacker would craft a malicious metadata buffer and use that buffer to trigger the vulnerability in the ntfs_read_metadata() function.

Original References and Resources

For those interested in delving deeper, here are some links to the original references, vulnerability research, and patch information:

1. NTFS-3G Repository: The source code of the NTFS-3G software can be found at the official NTFS-3G GitHub repository.

2. CVE-2022-40284 Vulnerability Details: For more information on the vulnerability and its potential impact, refer to the official CVE-2022-40284 record.

3. Vulnerability Research: For a detailed write-up on the vulnerability and discovery process, read this research blog post from the security researcher who discovered the issue.

4. Patch Information: The patch for this vulnerability can be found in the following NTFS-3G commit on GitHub. Be sure to update your installation of NTFS-3G to version 2022.10.3 or later to mitigate the risk posed by this vulnerability.

Conclusion

CVE-2022-40284 is an important vulnerability in NTFS-3G, a widely-used software for connecting NTFS file systems across multiple operating systems. Given the potential for code execution and privilege escalation, system administrators are strongly urged to review their installations and ensure that the patched version is in use. Additionally, it is crucial to follow the "principle of least privilege" and not grant excessive permissions to NTFS-3G binary, so as to minimize the potential impact of this vulnerability.

Timeline

Published on: 11/06/2022 23:15:00 UTC
Last modified on: 11/22/2022 02:15:00 UTC