Dear LinuxPatch Readers,
Recently, a significant vulnerability was identified in GNU Emacs, specifically within the Ruby programming environment. This vulnerability, registered as CVE-2022-48338, affects versions up to 28.2 and carries a high severity rating with a CVSS score of 7.3. Our goal today is to demystify this issue, helping you understand its impact and the steps you should consider to secure your systems.
GNU Emacs is an extensible, customizable, free/libre text editor – and more. At its core, Emacs is designed for text editing, but it's capable of much more. Users can code in several programming languages, including Ruby, by enabling specific modes. One such mode, ruby-mode, provides functionalities specific to Ruby programming.
The vulnerability discovered, CVE-2022-48338, arises within the 'ruby-mode.el' script of Emacs, specifically within a function designed to enhance Ruby coding by finding library files. The function in question, 'ruby-find-library-file', is vulnerable to local command injection attacks. Generally, this function allows users to utilize a keyboard shortcut (C-c C-f) to search for Ruby library files using the 'gem' command-line tool, which is a package manager for Ruby.
However, the function did not properly sanitize user input for feature names, allowing for external command execution. This means that if a user were to open a malicious Ruby file containing specially crafted inputs, it could potentially execute arbitrary commands on the user’s system under the permissions of the user running Emacs.
This vulnerability could be exploited by an attacker to perform actions like modifying files, installing malicious software, or stealing sensitive data, assuming they can get the target to open a malicious file with Emacs in Ruby mode. The risk is particularly significant because Emacs runs with the user's privileges, potentially providing broad access to an attacker.
It is crucial for users of GNU Emacs who work with Ruby to be aware of this vulnerability and take immediate steps to mitigate potential risks:
As always, staying informed about security advisories and maintaining a proactive security posture will help protect you from potential threats.
The discovery of CVE-2022-48338 underscores the importance of software security, especially in tools that we often take for granted as being secure. The collaborative nature of the open-source community and the responsiveness of software maintainers are key elements in addressing such vulnerabilities swiftly. We at LinuxPatch aim to keep you informed and prepared against such security threats. Stay vigilant, update regularly, and ensure your systems are safeguarded against potential intrusions.