CVE-2003-0839 in Windows
Summary
by MITRE
Directory traversal vulnerability in the "Shell Folders" capability in Microsoft Windows Server 2003 allows remote attackers to read arbitrary files via .. (dot dot) sequences in a "shell:" link.
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Analysis
by VulDB Data Team • 09/17/2018
The vulnerability described in CVE-2003-0839 represents a classic directory traversal flaw that existed within Microsoft Windows Server 2003's Shell Folders functionality. This security weakness specifically affects how the operating system processes shell: protocol links, which are used to access various system folders and resources through the Windows shell interface. The vulnerability stems from insufficient input validation when processing directory path sequences, allowing malicious actors to manipulate file access through crafted dot-dot sequences in shell links.
The technical implementation of this flaw occurs within the Windows shell component responsible for handling shell: protocol URLs. When a user or application accesses a shell: link containing directory traversal sequences such as ..\..\\ or similar constructs, the system fails to properly sanitize these paths before attempting to resolve them. This inadequate validation creates an opportunity for attackers to bypass normal file system access controls and navigate to arbitrary locations within the file system hierarchy. The vulnerability specifically targets the Shell Folders capability, which is part of the broader Windows shell infrastructure that manages how users and applications interact with system resources through standardized protocols.
The operational impact of this vulnerability is significant as it enables remote attackers to potentially access sensitive system files, configuration data, and user information without proper authentication or authorization. An attacker could exploit this weakness to read critical system files, access user documents, examine registry-related data, or potentially discover information about the system's configuration and network setup. The remote nature of the attack means that an attacker does not need local system access or physical presence to exploit this vulnerability, making it particularly dangerous in networked environments where Windows Server 2003 systems are exposed to external networks. This type of vulnerability directly relates to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and credential access. Attackers could leverage this weakness as part of a broader attack chain to gather intelligence about the target system or to access files that contain sensitive information such as passwords, configuration settings, or system credentials. The vulnerability's classification as a directory traversal issue places it within the category of attacks that attempt to access files outside of their intended scope, making it a common target for attackers seeking to expand their access within a compromised system. Organizations running Windows Server 2003 systems were particularly vulnerable to this type of attack due to the widespread use of shell: protocol links in various system components and user interfaces.
Mitigation strategies for CVE-2003-0839 should focus on implementing proper input validation and sanitization within the shell component that processes these protocol links. System administrators should ensure that all shell: protocol links are properly validated before processing, with special attention to eliminating or properly encoding directory traversal sequences. The most effective long-term solution involves applying the appropriate security patches from Microsoft that address the underlying shell folder processing logic. Organizations should also consider implementing network segmentation and access controls to limit exposure of vulnerable systems to untrusted networks, while monitoring for suspicious shell: protocol usage patterns that might indicate attempted exploitation. Additionally, regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of this vulnerability within the organization's infrastructure, as Windows Server 2003 reached end-of-life and no longer receives security updates from Microsoft.