FastNetMon Juniper Plugin OS Command Injection Vulnerability CVE-2026-48687

Vulnerability Overview CVE-2026-48687: OS Command Injection in FastNetMon's Juniper Plugin Log Function Vulnerability Description: The function in FastNetMon's Juniper plugin ( ) contains an OS command injection vulnerability. This function accepts a message string and uses the command to write it to a temporary log file. An attacker can execute arbitrary commands by crafting a parameter containing shell metacharacters. CVSS Score: 8.1 (High) CWE: CWE-78 (OS Command Injection) Affected Versions: FastNetMon Community Edition <= 1.2.9 Vulnerable Component: , function , lines 115-119 Attack Vector: Indirect Remote (via attack notification pipeline) Discoverer: Lorikeet Security Impact Scope Affected Component: FastNetMon Community Edition <= 1.2.9 Impact Path: An attacker can execute arbitrary commands by crafting a parameter containing shell metacharacters. Potential Impact: An attacker can exploit this vulnerability to execute arbitrary commands, potentially leading to complete system compromise. Remediation Correct Remediation Methods 1. Replace with PHP's File API: 2. Use to Escape Input: Compensating Controls Disable the Juniper Plugin: If the Juniper plugin is not needed, disable it. Audit IP Canonicalization Paths: Ensure IP addresses are properly canonicalized before being passed to the script. Run the Script with Low Privileges: Reduce the permissions under which the script executes. Restrict Shell Access on FastNetMon Hosts: Prevent unauthorized users or processes from directly invoking the notification script. Disclosure Timeline 2026-04-25: Vulnerability discovered during a source code audit of FastNetMon Community Edition 1.2.9 by Lorikeet Security. 2026-04-25: CVE ID requested from MITRE. 2026-04-25: FastNetMon LTD notified. 2026-05-22: CVE-2026-48687 assigned by MITRE. TBD: Vendor response. TBD: Fix released. 2026-05-23: Lorikeet Security publishes a responsible disclosure report. Exploit Code Example Summary The function in FastNetMon's Juniper plugin contains an OS command injection vulnerability, allowing an attacker to execute arbitrary commands by crafting a parameter containing shell metacharacters. It is recommended to apply the above remediation methods promptly and implement compensating controls to mitigate risk.

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FastNetMon Juniper Plugin OS Command Injection Vulnerability CVE-2026-48687