CVE-2015-6672 in Netscaler Application Delivery Controller
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Administrative Web Interface in Citrix NetScaler Application Delivery Controller (ADC) and NetScaler Gateway before 10.1 Build 132.8, 10.5 before Build 57.7, and 10.5e before Build 56.1505.e allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 06/15/2022
The CVE-2015-6672 vulnerability represents a critical cross-site scripting flaw discovered in Citrix NetScaler Application Delivery Controller and NetScaler Gateway products. This vulnerability specifically affects the administrative web interface component of these network security appliances, creating a significant attack surface that could be exploited by remote adversaries. The affected versions include various releases prior to specific build numbers, indicating this was a widespread issue affecting multiple product lines and release branches. The vulnerability's presence in the administrative interface is particularly concerning as it could potentially provide attackers with access to sensitive management functions and system configurations.
The technical flaw manifests as an insufficient input validation mechanism within the administrative web interface of Citrix NetScaler products. Attackers can leverage unspecified vectors to inject arbitrary web scripts or HTML content into the application's response handling. This injection occurs at the point where user-supplied input is processed and rendered back to the browser without proper sanitization or encoding. The vulnerability's classification as XSS (CWE-79) demonstrates that the system fails to properly escape or validate user-provided data before incorporating it into dynamically generated web content. This allows malicious scripts to execute within the context of a victim's browser session, potentially leading to session hijacking, data exfiltration, or further exploitation of the compromised system.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with a potential foothold for more sophisticated attacks against the Citrix NetScaler infrastructure. An attacker who successfully exploits this vulnerability could potentially access the administrative interface, modify system configurations, or gain unauthorized access to network traffic management functions. The attack vector being remote means that exploitation does not require physical access to the device, making it particularly dangerous in environments where these appliances are exposed to untrusted networks. This vulnerability could enable attackers to manipulate load balancing configurations, redirect traffic, or even establish persistent access points within the network infrastructure.
Organizations utilizing affected Citrix NetScaler versions should immediately implement mitigation strategies to address this vulnerability. The primary recommendation involves applying the vendor-provided security patches and updates that specifically address this XSS flaw. Additionally, network segmentation and access controls should be strengthened to limit exposure of the administrative interfaces to only trusted administrative networks. Implementing web application firewalls and content security policies can provide additional layers of protection against similar injection attacks. The vulnerability's classification under ATT&CK technique T1059.001 (Command and Scripting Interpreter) highlights the potential for attackers to leverage such weaknesses for broader system compromise, making prompt remediation essential for maintaining network security posture.