CVE-2002-2426 in Presentation Server
Summary
by MITRE
Cross-site request forgery (CSRF) vulnerability in Citrix Presentation Server 4.0 and 4.5, MetaFrame Presentation Server 3.0, and Access Essentials 1.0 through 2.0 allows remote attackers to execute arbitrary published applications, and possibly other programs, as authenticated users via the InitialProgram key in an ICA connection. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 02/05/2019
The CVE-2002-2426 vulnerability represents a critical cross-site request forgery flaw affecting multiple Citrix server products including Presentation Server 4.0 and 4.5, MetaFrame Presentation Server 3.0, and Access Essentials 1.0 through 2.0. This vulnerability operates at the application layer and specifically targets the ICA (Independent Computing Architecture) connection mechanism that Citrix uses for remote desktop and application delivery services. The flaw stems from insufficient validation of the InitialProgram parameter within ICA connection requests, allowing malicious actors to manipulate the program execution context. According to CWE-352, this vulnerability directly maps to cross-site request forgery conditions where an attacker can trick authenticated users into executing unintended actions on a web application. The vulnerability exists because the system fails to properly authenticate and validate the source of ICA connection requests, particularly when the InitialProgram key is involved in specifying which application should be launched upon connection.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious ICA connection request that includes a specially crafted InitialProgram parameter. This parameter controls which application gets executed when a user connects to the Citrix server through the ICA protocol. When an authenticated user visits a malicious website or clicks on a crafted link, the attacker can leverage the CSRF flaw to force the user's browser to establish an ICA connection with specific program parameters. The vulnerability allows execution of arbitrary published applications and potentially other programs as if they were initiated by the authenticated user. This represents a serious privilege escalation issue since the attacker can leverage legitimate user credentials and execute programs with the same permissions and access rights as the authenticated user. The attack vector typically involves social engineering techniques where victims are tricked into visiting malicious websites that contain hidden ICA connection requests.
The operational impact of CVE-2002-2426 is severe and multifaceted across enterprise environments relying on Citrix server products. Organizations using affected versions face potential unauthorized program execution, data compromise, and system integrity violations. Attackers can leverage this vulnerability to execute malicious applications, access sensitive data, or perform actions that the authenticated user is authorized to perform. The vulnerability particularly affects environments where Citrix servers are exposed to untrusted networks or where users have elevated privileges. From an ATT&CK framework perspective, this vulnerability maps to T1566 (Phishing) and T1078 (Valid Accounts) as attackers require legitimate user credentials and social engineering to exploit the flaw. The impact extends beyond simple application execution to potential lateral movement within networks, as authenticated users often have access to internal resources and services. Organizations may experience unauthorized access to corporate applications, potential data exfiltration, and disruption of business operations.
Mitigation strategies for CVE-2002-2426 involve multiple layers of security controls to address the CSRF vulnerability in Citrix environments. Organizations should immediately upgrade to patched versions of Citrix Presentation Server and MetaFrame products, as Citrix released security updates specifically addressing this vulnerability. Network segmentation and access controls should be implemented to limit exposure of Citrix servers to untrusted networks, reducing the attack surface available to potential attackers. Implementing proper input validation and authentication mechanisms within ICA connection handling processes can help prevent unauthorized program execution. Security administrators should also consider deploying web application firewalls and monitoring solutions that can detect anomalous ICA connection patterns. From a compliance perspective, this vulnerability affects organizations subject to regulations requiring secure application delivery and access control measures. The fix typically involves applying vendor security patches and ensuring that all affected Citrix server installations are updated to versions that properly validate ICA connection parameters. Additionally, user education and awareness programs should be implemented to reduce the success rate of social engineering attacks that exploit this vulnerability.