A recent security vulnerability has been identified in the File Open Source project - specifically, versions before 5.43. The stack-based buffer over-read in file_copystr in funcs.c can pose a serious risk to systems running the vulnerable software. In this article, we will examine the severity of the issue, provide code snippets illustrating the problem, and discuss the potential exploit details for CVE-2022-48554. We will also provide links to the original security notices and resources so that you can stay informed about the latest developments.


Before diving into the technical details, it is essential to understand what the File Open Source project is. File is a software application used in Unix-based systems to identify the file format of a particular input file, allowing you to process it accordingly. It is widely used and considered a fundamental tool for Unix-like operating systems.

The Vulnerability: CVE-2022-48554

An issue was discovered in the File Open Source project before version 5.43 where there is a stack-based buffer over-read in the file_copystr() function in funcs.c. This vulnerability is identified as CVE-2022-48554 and can potentially lead to unauthorized access, denial of service (DoS), or even code execution in some cases.

In simple terms, a buffer over-read occurs when a program reads data beyond the boundaries of a buffer, causing unintended consequences. In this case, the vulnerability is found in the file_copystr() function in the funcs.c file of the affected application.

Code Snippet Illustrating the Problem

In the source code for the funcs.c file, the problematic code can be found within the file_copystr() function. Here is an example of how the issue might look:

char *
file_copystr(char *buf, size_t blen, const char *src, size_t *len)
    const char *send = src + *len;
    char *bend = buf + blen - 1;
    char *bp = buf;

    while(src < send && bp < bend)
        *bp++ = *src++;
    *bp = '\';
    return buf;

The problem here is that the function will continue reading until it reaches the user-defined "send" pointer (which points to the end of the source buffer). The function does not properly check the buffer's size, which can result in over-reading the buffer and reading data beyond the intended scope.

Exploit Details

An attacker could potentially leverage this vulnerability to manipulate the target system or cause a denial of service (DoS) by executing a specially crafted file on an affected system using the out-of-boundary data to create unpredictable results.

As of now, there are no publicly disclosed reliable exploits for this vulnerability, but this could change at any time.

Original References and Resources

It's essential to consult reliable sources to stay up-to-date on security issues like this. Use the links below to access the original security notices and related materials.

1. MITRE CVE details: CVE-2022-48554
2. National Vulnerability Database (NVD): CVE-2022-48554
3. Official File project website: https://www.darwinsys.com/file/

Recommendations for Mitigation

To reduce the risk of exposure to this vulnerability, it is recommended that you upgrade to File version 5.43 or later, which contains patches for the problem. If your system does not have an available update, consider contacting your software vendor for guidance or implementing additional security measures, such as limiting access to the affected application or network segmentation, to reduce the risk of exploitation.

Stay vigilant and keep your systems up-to-date to stay protected against security vulnerabilities like CVE-2022-48554. Always refer to reputable resources and follow best practices to reduce your risk.


Published on: 08/22/2023 19:16:00 UTC
Last modified on: 09/05/2023 05:15:00 UTC