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How the CVE Works:
The vulnerability, CVE-2025-12121, is a command injection flaw in the Lite XL code editor. It originates in the `system.exec` function, which is used to execute shell commands from within the application. The function constructs shell commands by concatenating user-influenced input without proper sanitization or escaping. This insecure construction occurs in multiple core and plugin files: `core.lua` (for opening project directories), `rootview.lua` (for handling drag-and-drop file operations), and `treeview.lua` (for the “open in system” command). An attacker can craft malicious filenames or directory paths containing shell metacharacters (like semicolons or backticks). When these are passed to the vulnerable `system.exec` calls, the embedded commands are executed by the system’s shell. This allows an attacker to run arbitrary operating system commands with the same privileges as the Lite XL process. The exploit requires the attacker to influence the input, which could be achieved by tricking a user into opening a maliciously named file or project. No validation is performed on the input before it is incorporated into the shell command string. Consequently, the vulnerability bypasses any intended application logic, directly leading to a complete compromise of the underlying shell environment accessible to the application.
Platform: Lite XL
Version: 2.1.8 prior
Vulnerability : Command Injection
Severity: Critical
date: 2025-11-20
Prediction: 2025-12-20
What Undercode Say:
Analytics:
Searching for vulnerable system.exec patterns in Lua code
grep -r "system.exec" /path/to/litexl/ --include=".lua"
Example of a malicious payload in a filename
touch 'file; rm -rf /important .txt'
Simulating command construction (Vulnerable)
user_input="malicious; cmd"
system.exec("open " .. user_input) Results in: open malicious; cmd
How Exploit:
- Attacker creates a file with a name containing shell commands (e.g.,
payload; cat /etc/passwd .txt). - User drags this file into the Lite XL editor window or uses “Open in System” on it.
- The application passes the unsanitized filename to
system.exec. - The shell executes the intended command (
open payload) and then the injected command (cat /etc/passwd).
Protection from this CVE:
Sanitize all user input for shell metacharacters.
Use command argument lists instead of string concatenation.
Apply the official patch from Lite XL developers.
Update to a fixed version immediately upon release.
Impact:
Confidentiality: High (Unauthorized file system read).
Integrity: High (Unauthorized file system modification).
Availability: High (Potential for system disruption via rm -rf).
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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