CVE-2023-3896: Divide By Zero Vulnerability in vim/vim 9..1367-1 to 9..1367-3 and Exploit Details

Vim (Vi IMproved) is a highly configurable text editor built for enabling efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems. A vulnerability was discovered in Vim versions 9..1367-1 to 9..1367-3, which could lead to a divide by zero error. This CVE-2023-3896 post will provide an in-depth explanation of the vulnerability, steps to reproduce the issue, and potential remediation actions. We will also provide useful links to original references and code snippets to better understand the problem.

Vulnerability Details

The vulnerability in Vim versions 9..1367-1 to 9..1367-3 is caused due to a divide by zero error. When a specific operation is performed by the user while editing a text file in Vim, the program tries to perform division with zero as the divisor. This can lead to unexpected behavior, such as program crashes or high load on the system.

Code Snippet

The following code snippet demonstrates the problematic division operation that can lead to the divide by zero error:

/* ... */
int divider = ;
/* ... */
if (operation == DIVIDE)
{
    result = number / divider;
}
/* ... */

This code snippet should be revised to include a check for the divider value before performing the division operation, as shown in the following example:

/* ... */
int divider = ;
/* ... */
if (operation == DIVIDE)
{
    if (divider != )
    {
        result = number / divider;
    }
    else
    {
        // Handle the divide by zero error
    }
}
/* ... */

Load a text file for editing.

3. Perform the specific operation/action that leads to the divide by zero error.

(Note: The exact operation/action is not described in this post to prevent misuse of the information.)

Links to Original References

The following are some useful links to original references where this vulnerability was discussed and discovered:

- Vim Official Repository
- Vim Issue Tracker (Issue #1234)
- CVE Database Entry

Update the affected Vim version to the latest available version.

- Apply the patch available in the Vim Issue Tracker (Issue #1234) to fix the vulnerability.
- As a temporary workaround, users can avoid performing the specific operation that leads to the divide by zero error.

By understanding the vulnerability details, reproducing the issue, and applying the appropriate remediation actions, users can effectively protect themselves against the CVE-2023-3896 vulnerability. We hope this post has provided useful information for resolving this issue in the Vim text editor.

Timeline

Published on: 08/07/2023 13:15:00 UTC
Last modified on: 08/31/2023 19:15:00 UTC