CVE-2010-2991 in Online Plug-in
Summary
by MITRE
The IICAClient interface in the ICAClient library in the ICA Client ActiveX Object (aka ICO) component in Citrix Online Plug-in for Windows for XenApp & XenDesktop before 12.0.3 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted HTML document that triggers the reading of a .ICA file.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/21/2025
The vulnerability identified as CVE-2010-2991 represents a critical security flaw within Citrix Online Plug-in for Windows components that affect XenApp and XenDesktop environments. This issue specifically targets the IICAClient interface within the ICAClient library of the ICA Client ActiveX Object, commonly referred to as the ICO component. The vulnerability stems from improper handling of crafted HTML documents that can trigger the processing of malicious .ICA files through the ActiveX interface. This flaw exists in Citrix Online Plug-in versions prior to 12.0.3, making a substantial portion of deployed Citrix environments susceptible to exploitation.
The technical mechanism behind this vulnerability involves memory corruption that occurs when the IICAClient interface processes malformed .ICA files through a specially crafted HTML document. When a user visits a malicious website or opens a compromised email attachment containing such HTML content, the ActiveX control automatically attempts to parse the embedded .ICA file. This parsing process fails to properly validate input parameters and memory allocation, leading to buffer overflows or other memory corruption conditions. The vulnerability is classified as a heap-based buffer overflow under CWE-121, which allows attackers to manipulate memory layout and potentially execute arbitrary code at the privileges of the compromised user.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and denial of service conditions. Attackers can leverage this weakness to gain remote code execution capabilities on targeted systems, potentially escalating privileges and establishing persistent access to corporate networks. The memory corruption can also result in application crashes or system instability, creating denial of service scenarios that disrupt legitimate business operations. According to ATT&CK framework, this vulnerability maps to T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) techniques, as attackers can execute malicious code through the compromised ActiveX interface.
Mitigation strategies for CVE-2010-2991 require immediate patch deployment to upgrade the Citrix Online Plug-in to version 12.0.3 or later, which contains the necessary fixes to prevent the memory corruption conditions. Organizations should also implement network-level controls to block access to known malicious domains and monitor for suspicious ActiveX-related network traffic. Browser security configurations should be adjusted to restrict ActiveX control loading, and users should be educated about avoiding untrusted websites and email attachments. Additionally, security teams should conduct comprehensive vulnerability assessments to identify all systems running affected Citrix components and ensure proper patch management procedures are in place to prevent similar issues in the future. The vulnerability demonstrates the critical importance of proper input validation in ActiveX controls and highlights the risks associated with legacy components that may not receive adequate security updates.