CVE-2005-2122 in Windows
Summary
by MITRE
Windows Shell for Microsoft Windows 2000 SP4, XP SP1 and SP2, and Server 2003 allows remote attackers to execute arbitrary commands via a shortcut (.lnk) file with long font properties that lead to a buffer overflow in the Client/Server Runtime Server Subsystem (CSRSS), a different vulnerability than CVE-2005-2118.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability described in CVE-2005-2122 represents a critical buffer overflow condition within the Windows Shell component that affects multiple versions of Microsoft Windows including Windows 2000 SP4, Windows XP SP1 and SP2, and Windows Server 2003. This flaw specifically targets the Client/Server Runtime Server Subsystem (CSRSS) which serves as a critical component in Windows operating systems responsible for managing console windows and other user interface elements. The vulnerability manifests when a malicious shortcut file (.lnk) containing excessively long font properties is processed by the Windows Shell, creating a scenario where memory corruption occurs during the parsing of these extended font specifications.
The technical mechanism behind this vulnerability involves the improper handling of font property data within the shortcut file parsing logic. When the Windows Shell encounters a .lnk file with font properties that exceed the allocated buffer size, it fails to perform adequate bounds checking or input validation before copying the font data into memory. This results in a classic buffer overflow condition where the excess data overwrites adjacent memory locations, potentially including return addresses and other critical program state information. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, representing a fundamental flaw in memory management that has been exploited by attackers for privilege escalation and arbitrary code execution.
The operational impact of this vulnerability extends far beyond simple denial of service conditions, as it provides remote attackers with the capability to execute arbitrary commands on affected systems. This represents a significant elevation in threat potential since attackers can craft malicious .lnk files that, when opened or even previewed by users, will trigger the buffer overflow and allow for code execution with the privileges of the user who interacts with the file. The attack vector is particularly concerning because .lnk files are commonly shared through email attachments, network shares, and removable media, making them an effective tool for social engineering attacks that can bypass traditional security measures. This vulnerability directly maps to ATT&CK technique T1059.001 for command and scripting interpreter and T1203 for Exploitation for Client Execution, demonstrating how attackers can leverage this flaw to establish persistent access and conduct further malicious activities.
Mitigation strategies for CVE-2005-2122 should focus on immediate patch deployment through Microsoft's security updates, as the vulnerability was addressed through official service packs and security bulletins released by Microsoft. Organizations must also implement defensive measures including user education about suspicious file attachments, network-level filtering of .lnk files, and disabling automatic preview features for potentially malicious file types. Additionally, system administrators should consider implementing application whitelisting policies that restrict execution of untrusted shortcut files and ensure that all systems are running the latest security updates. The vulnerability highlights the importance of proper input validation and bounds checking in system components, particularly those handling user-provided data, and serves as a reminder of the critical nature of maintaining up-to-date security patches across all operating system components.