CVE-2005-0819 in NetWare
Summary
by MITRE
The xvesa code in Novell Netware 6.5 SP2 and SP3 allows remote attackers to redirect the xsession without authentication via a direct request to GUIMirror/Start.
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Analysis
by VulDB Data Team • 06/07/2017
The vulnerability described in CVE-2005-0819 represents a significant security flaw in the xvesa implementation within Novell Netware 6.5 service packs 2 and 3. This issue stems from improper authentication mechanisms within the graphical user interface component that handles xsession redirection. The vulnerability specifically affects the GUIMirror/Start endpoint which serves as a direct interface for managing graphical sessions within the Netware environment. Attackers can exploit this weakness by sending crafted requests directly to this endpoint without requiring valid credentials, effectively bypassing the standard authentication protocols that should govern access to graphical session management functions.
The technical nature of this vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems. The flaw exists in the implementation of the xvesa subsystem that provides X Window System support for Netware environments. When a remote attacker sends a request to the GUIMirror/Start endpoint, the system fails to properly validate the authenticity of the requestor before executing the xsession redirection process. This creates a path for unauthorized users to gain control over graphical sessions, potentially allowing them to access sensitive graphical interfaces, manipulate user sessions, or redirect sessions to malicious endpoints.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential session hijacking and privilege escalation scenarios. Since the xsession redirection functionality is typically used for managing user graphical environments, an attacker who successfully exploits this vulnerability could potentially intercept user sessions, access graphical applications, or even redirect users to phishing or malicious endpoints. The lack of authentication requirements for this critical function makes it particularly dangerous in enterprise environments where Netware systems might be exposed to untrusted networks or where users might be accessing graphical interfaces from potentially compromised workstations.
This vulnerability demonstrates the importance of implementing proper access controls even for seemingly benign administrative functions. The ATT&CK framework categorizes this issue under privilege escalation and defense evasion techniques, as attackers can leverage the lack of authentication to gain unauthorized access to graphical session management capabilities. Organizations running Novell Netware 6.5 SP2 or SP3 should consider this vulnerability as part of a broader security assessment, particularly focusing on the exposure of graphical interfaces to external networks. The vulnerability also highlights the need for network segmentation and the principle of least privilege when implementing graphical session management services.
Mitigation strategies should include immediate patching of the affected Netware versions, implementing network-level restrictions to limit access to the GUIMirror/Start endpoint, and ensuring that graphical session management services are not exposed to untrusted networks. Additionally, organizations should conduct comprehensive security audits of their Netware implementations to identify other potential authentication bypass vulnerabilities and implement proper monitoring for unauthorized access attempts to graphical session management functions. The vulnerability serves as a reminder of the critical importance of authentication mechanisms in all system components, particularly those that provide access to user sessions and graphical interfaces.