CVE-2017-2336 Explained : Impact and Mitigation

A reflected cross-site scripting vulnerability in the NetScreen WebUI of Juniper Networks Juniper NetScreen Firewall+VPN running ScreenOS allows attackers to inject HTML/JavaScript content into the management session of other users, potentially leading to unauthorized command execution.

Understanding CVE-2017-2336

This CVE involves a critical vulnerability in Juniper Networks ScreenOS that impacts the SSG Series.

What is CVE-2017-2336?

The vulnerability enables attackers to insert malicious code into the WebUI, compromising the administrator's session and executing commands with admin privileges.

The Impact of CVE-2017-2336

CVSS Base Score: 9.6 (Critical)
Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: High

Technical Details of CVE-2017-2336

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows for reflected cross-site scripting in the NetScreen WebUI, affecting ScreenOS versions prior to 6.3.0r24 on SSG Series.

Affected Systems and Versions

Vendor: Juniper Networks
Product: ScreenOS
Affected Version: 6.3.0 prior to 6.3.0r24
Platforms: SSG Series

Exploitation Mechanism

Attackers can exploit this vulnerability by injecting HTML/JavaScript content into the management session of users, including administrators, via the NetScreen WebUI.

Mitigation and Prevention

Protect your systems from CVE-2017-2336 with the following measures:

Immediate Steps to Take

Utilize access lists or firewall filters to restrict WebUI access to trusted hosts.

Long-Term Security Practices

Regularly update ScreenOS to the latest version to patch known vulnerabilities.

Patching and Updates

Update to ScreenOS 6.3.0r24 or later to mitigate the XSS vulnerability.