CVE-2016-6493 in XenApp
Summary
by MITRE
Citrix XenApp 6.x before 6.5 HRP07 and 7.x before 7.9 and Citrix XenDesktop before 7.9 might allow attackers to weaken an unspecified security mitigation via vectors related to memory permission.
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Analysis
by VulDB Data Team • 03/17/2019
The vulnerability identified as CVE-2016-6493 affects Citrix XenApp and XenDesktop products across multiple versions, representing a significant security weakness in memory permission handling mechanisms. This flaw exists in Citrix XenApp versions 6.x before 6.5 HRP07 and 7.x before 7.9, as well as in Citrix XenDesktop versions before 7.9, indicating a widespread impact across the Citrix virtualization ecosystem. The vulnerability stems from insufficient memory permission controls that could potentially be exploited by malicious actors to bypass security mitigations designed to protect system resources and data integrity.
The technical nature of this vulnerability involves memory permission manipulation that allows attackers to weaken security controls through unspecified vectors related to memory access patterns. This type of flaw typically falls under the category of memory corruption vulnerabilities, which can be classified as CWE-125 in the Common Weakness Enumeration system, representing out-of-bounds read conditions that may lead to information disclosure or privilege escalation. The vulnerability's impact is particularly concerning because it affects the fundamental memory management protections that are essential for maintaining system security boundaries and preventing unauthorized access to sensitive data and system resources.
From an operational standpoint, this vulnerability creates a substantial risk for organizations utilizing Citrix virtualization solutions, as attackers could potentially exploit the weakened memory permission controls to gain elevated privileges or access restricted system components. The attack surface extends to any environment where Citrix XenApp or XenDesktop is deployed, particularly in enterprise environments where these products are commonly used for remote desktop and application virtualization services. The vulnerability's exploitation could lead to unauthorized access to user sessions, data breaches, or the potential for privilege escalation within the virtualized environment, making it a critical concern for cybersecurity teams managing Citrix infrastructure.
The security implications of CVE-2016-6493 align with techniques described in the MITRE ATT&CK framework under the privilege escalation and defense evasion tactics, where attackers may leverage memory corruption vulnerabilities to bypass security controls. Organizations should prioritize immediate remediation through the application of Citrix's official patches and updates, which address the memory permission handling weaknesses. System administrators should also implement additional monitoring for suspicious memory access patterns and ensure that proper access controls and network segmentation are in place to limit the potential impact of such vulnerabilities. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the need for comprehensive vulnerability management programs to protect against memory-based security flaws that could compromise entire virtualized infrastructures.