CVE-2014-2781 in Windows
Summary
by MITRE
Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 do not properly restrict the exchange of keyboard and mouse data between programs at different integrity levels, which allows attackers to bypass intended access restrictions by leveraging control over a low-integrity process to launch the On-Screen Keyboard (OSK) and then upload a crafted application, aka "On-Screen Keyboard Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 12/17/2024
This vulnerability exists in multiple versions of the microsoft windows operating system and represents a critical privilege escalation flaw that undermines the operating system's integrity level protection mechanisms. The issue stems from improper handling of input device data exchange between processes running at different integrity levels, specifically affecting the on-screen keyboard osk.exe application which is typically launched by low-integrity processes. The vulnerability allows attackers to leverage control over a low-integrity process to execute the on-screen keyboard and subsequently upload a malicious application that can elevate privileges beyond the intended security boundaries.
The technical flaw resides in the operating system's failure to properly enforce integrity level restrictions when processing keyboard and mouse input data between different security contexts. When a low-integrity process attempts to launch the on-screen keyboard, the system should prevent such operations from being used as a vector for privilege escalation. However, the vulnerability allows attackers to manipulate this process flow to execute arbitrary code with elevated privileges, effectively bypassing the mandatory integrity control mechanisms that are fundamental to windows security architecture. This weakness is particularly dangerous because it directly violates the principle of least privilege and can be exploited without requiring physical access or advanced exploitation techniques.
The operational impact of this vulnerability is severe as it provides attackers with a straightforward method to escalate privileges from low-integrity to high-integrity contexts. Attackers can exploit this vulnerability by first compromising a low-integrity process through various means such as web browser exploits or social engineering, then using this foothold to launch the on-screen keyboard and upload a malicious payload. The vulnerability affects a broad range of windows versions including vista, server 2008, 7, 8, 8.1, and their respective server editions, making it particularly widespread. The attack vector is relatively simple to execute and does not require specialized knowledge or expensive tools, which increases the likelihood of successful exploitation in real-world scenarios.
The vulnerability aligns with common attack patterns identified in the mitre attack framework, specifically relating to privilege escalation techniques and the use of legitimate system tools for malicious purposes. It can be categorized under attack technique t1068 which involves exploiting local privilege escalation vulnerabilities, and also relates to t1059 which covers command and scripting interpreter usage. From a cwe perspective, this vulnerability maps to cwe-284 which describes improper access control, and cwe-787 which covers out-of-bounds write conditions. The flaw demonstrates poor input validation and inadequate process isolation mechanisms that should prevent cross-integrity level data exchange. Organizations affected by this vulnerability face significant risk of unauthorized system compromise and potential lateral movement within their networks.
Mitigation strategies should include applying the relevant microsoft security updates that address this specific vulnerability, implementing application whitelisting policies to prevent unauthorized execution of the on-screen keyboard, and configuring proper integrity level restrictions for input device handling. System administrators should also consider disabling unnecessary features such as the on-screen keyboard for users who do not require it, and monitor for suspicious process execution patterns that may indicate exploitation attempts. The most effective long-term solution involves ensuring all systems are patched with the appropriate security updates and maintaining robust security configurations that enforce strict integrity level enforcement throughout the operating system. Additionally, organizations should implement comprehensive monitoring solutions that can detect anomalous behavior related to privilege escalation attempts and input device manipulation.