CVE-2008-3485 in MetaFrame Presentation Server
Summary
by MITRE
Untrusted search path vulnerability in Citrix MetaFrame Presentation Server allows local users to gain privileges via a malicious icabar.exe placed in the search path.
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Analysis
by VulDB Data Team • 11/22/2017
The vulnerability described in CVE-2008-3485 represents a critical untrusted search path issue within Citrix MetaFrame Presentation Server, a widely deployed terminal server solution that enables multiple users to access applications and desktops from centralized servers. This flaw resides in the application's handling of executable file paths during the loading process, specifically involving the icabar.exe component that serves as a critical system utility for managing application bars and user interface elements within the presentation server environment. The vulnerability stems from the application's failure to properly validate or sanitize the search paths used to locate executable files, creating an opportunity for malicious actors to manipulate the system's execution flow through strategic placement of unauthorized binaries in predetermined locations.
The technical exploitation of this vulnerability occurs when a local attacker places a malicious version of icabar.exe in a directory that appears earlier in the system's PATH environment variable or in the application's designated search directories. When the legitimate MetaFrame Presentation Server application attempts to execute icabar.exe, the system loads the attacker-controlled binary instead of the legitimate one, effectively allowing privilege escalation from a standard user account to a higher privileged context. This type of vulnerability falls under the CWE-426 Untrusted Search Path category, which specifically addresses the security implications of allowing applications to execute binaries from untrusted or user-controllable locations. The flaw demonstrates a classic path traversal attack vector where the application's trust model is violated through improper path resolution mechanisms.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to execute arbitrary code with elevated privileges within the context of the presentation server environment. This capability allows malicious users to potentially access sensitive corporate data, modify system configurations, or establish persistent access points within the network infrastructure. The vulnerability is particularly concerning in enterprise environments where Citrix MetaFrame servers typically operate with elevated privileges and may have access to critical business applications and data repositories. Attackers can leverage this weakness to move laterally within the network, potentially compromising other systems that rely on the presentation server for authentication or application delivery services, aligning with techniques described in the ATT&CK framework under privilege escalation and lateral movement tactics.
Mitigation strategies for CVE-2008-3485 should focus on implementing proper input validation and path resolution practices within the MetaFrame Presentation Server environment. System administrators should ensure that the application's search paths are carefully configured to prioritize trusted locations and avoid including user-controllable directories in the execution path. The recommended approach includes implementing secure coding practices such as using absolute paths for executable references, validating file integrity through checksums or digital signatures, and restricting write permissions to system directories. Additionally, organizations should consider implementing application whitelisting solutions that prevent unauthorized executables from running within the environment, thereby reducing the attack surface for this class of vulnerability. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar path traversal issues in other applications within the enterprise infrastructure.