A heap-buffer overflow vulnerability (CVE-2025-22134) has been discovered in the popular text editor, Vim, that could potentially lead to arbitrary code execution or crashes under specific conditions. This vulnerability is triggered when a user switches to other buffers using the :all command while the visual mode is still activated. Vim will improperly end the visual mode and may try to access beyond the end of a line in a buffer, leading to the heap-buffer overflow. This issue has been fixed in Vim patch v9.1.1003.
Exploit Details
The vulnerability arises when a user has visual mode enabled while executing the :all ex command. The following code snippet demonstrates the potential for a heap-buffer overflow when interacting with Vim's buffers:
:set visualmode
:new
:all
In this example, the user first turns on the visual mode, then creates a new buffer, and finally switches to other buffers using the :all command. Due to the visual mode not being properly deactivated, Vim may attempt to access a position beyond the end of the buffer line, leading to a heap-buffer overflow.
Patch and Mitigation
Vim has released patch 9.1.1003 to address this vulnerability. The patch ensures that the visual mode is correctly reset before opening other windows and buffers. In addition, it introduces verification checks to ensure that Vim will not attempt to access a position if the position is greater than the corresponding buffer line.
To apply the patch and mitigate the vulnerability, users should simply update Vim to the latest version. You can find the latest release and the patch notes on their official GitHub repository.
Impact and Acknowledgements
The impact of this vulnerability is considered medium, as the user must have activated the visual mode when executing the :all ex command. However, it is crucial for Vim users to apply the patch to ensure the safe and proper functioning of the text editor.
The Vim project would like to express their gratitude to GitHub user gandalf4a for reporting and contributing to the identification of this issue.
Conclusion
In conclusion, the heap-buffer overflow in Vim when switching buffers using the :all command and visual mode active (CVE-2025-22134) poses a medium risk to users. Updating to Vim patch 9.1.1003 will correct the visual mode issue and add verification checks to prevent this vulnerability from being exploited. It is highly recommended for all users to update their Vim application to stay secure.
Timeline
Published on: 01/13/2025 21:15:14 UTC
Last modified on: 03/14/2025 10:15:16 UTC