CVE-2026-48687 Details

A command injection vulnerability has been identified in the FastNetMon Community Edition router integration plugin for Juniper devices, affecting versions through 1.2.9. The vulnerability arises in the logging function of the Juniper plugin, where unsanitized data from command-line arguments is directly concatenated into shell commands executed by the PHP 'exec()' function. This flaw allows for arbitrary command execution, as shell metacharacters in the injected data can be used to manipulate the command execution process. The issue is particularly concerning because the plugin can be invoked in ways that bypass FastNetMon's usual input sanitization, potentially leading to exploitation in future versions or through direct script invocation.

The vulnerability can be fixed by replacing the 'exec()' function with 'file_put_contents()' to write logs directly to a file without involving the shell. If 'exec()' must be used, it's essential to sanitize all input parameters with 'escapeshellarg()' to neutralize any shell metacharacters.