CVE-2013-6077 in XenDesktop
Summary
by MITRE
Citrix XenDesktop 7.0, when upgraded from XenDesktop 5.x, does not properly enforce policy rule permissions, which allows remote attackers to bypass intended restrictions.
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Analysis
by VulDB Data Team • 06/01/2021
The vulnerability identified as CVE-2013-6077 affects Citrix XenDesktop 7.0 systems that have been upgraded from XenDesktop 5.x versions. This represents a critical authorization bypass flaw that undermines the security controls implemented within the virtual desktop infrastructure. The issue specifically manifests during the upgrade process from legacy versions, where the system fails to properly enforce policy rule permissions that were previously established in the older version. This creates a persistent security gap that can be exploited by remote attackers to circumvent intended access controls and restrictions.
The technical root cause of this vulnerability stems from improper handling of policy enforcement mechanisms during the upgrade procedure. When Citrix XenDesktop 7.0 is installed on top of an existing XenDesktop 5.x environment, the system does not adequately validate or migrate the existing permission policies, resulting in a weakened security posture. The flaw operates at the policy enforcement layer, where access controls that should restrict user privileges and system access are not properly applied or maintained. This misconfiguration allows unauthorized users to gain access to resources and functionality that should be restricted based on established security policies.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it fundamentally compromises the integrity of the virtual desktop environment's security framework. Remote attackers can exploit this weakness to bypass authentication controls, access restricted administrative functions, and potentially escalate privileges within the virtual desktop infrastructure. The vulnerability affects organizations that have upgraded their XenDesktop environments, creating a window of opportunity for threat actors to exploit the inconsistent policy enforcement. This poses significant risks to data confidentiality, integrity, and availability, particularly in enterprise environments where virtual desktops contain sensitive corporate information.
Organizations should implement immediate mitigations including thorough policy validation after upgrades, enhanced monitoring of access controls, and verification of permission settings across all upgraded systems. The vulnerability aligns with CWE-284, which addresses improper access control issues, and relates to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. Security teams must conduct comprehensive audits of their upgraded environments to ensure proper policy enforcement and consider implementing additional access control measures. The remediation process should include complete policy reconfiguration, system hardening, and continuous monitoring to detect any unauthorized access attempts that may exploit this vulnerability. Organizations should also review their upgrade procedures to prevent similar issues in future deployments and maintain strict adherence to security best practices throughout their virtual desktop infrastructure lifecycle.