CVE-2009-4073 in Internet Explorer
Summary
by MITRE
The printing functionality in Microsoft Internet Explorer 8 allows remote attackers to discover a local pathname, and possibly a local username, by reading the dc:title element of a PDF document that was generated from a local web page.
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Analysis
by VulDB Data Team • 03/23/2025
The vulnerability described in CVE-2009-4073 represents a significant information disclosure flaw within Microsoft Internet Explorer 8's handling of PDF documents generated from local web pages. This security weakness specifically affects the printing functionality of the browser, where remote attackers can exploit the dc:title element of PDF documents to extract sensitive local system information. The vulnerability stems from how Internet Explorer processes and renders PDF content during the printing operation, creating an unintended information leak channel that can reveal local pathname structures and potentially user account names. This type of information disclosure vulnerability falls under the category of CWE-200, which encompasses weaknesses that result in the exposure of sensitive information to an attacker.
The technical mechanism behind this vulnerability involves the interaction between Internet Explorer's PDF rendering engine and the Dublin Core metadata elements embedded within PDF documents. When a local web page is converted to PDF format, the dc:title element may contain references to the local file system paths or user information that are inadvertently exposed during the printing process. This occurs because the PDF generation process does not properly sanitize or strip metadata that could reveal system-specific details, particularly when the document originates from a local source. The flaw is particularly concerning because it allows remote attackers to gather intelligence about the target system's local file structure and user environment without requiring direct system access or authentication.
The operational impact of this vulnerability extends beyond simple information disclosure, as the gathered pathname information and user details can serve as valuable reconnaissance data for attackers planning more sophisticated attacks. An attacker who successfully exploits this vulnerability can map local directory structures, potentially identifying sensitive application paths, configuration files, or user home directories that could be targeted in subsequent exploitation attempts. The exposure of local usernames could facilitate credential guessing attacks or social engineering efforts, while the pathname information might reveal system architecture details that could be used to tailor more effective attack vectors. This vulnerability aligns with ATT&CK technique T1083, which covers discovering file system permissions and directory listings, and represents a classic example of how seemingly benign browser functionality can become a vector for information leakage.
Mitigation strategies for CVE-2009-4073 should focus on both immediate remediation and long-term security hardening approaches. Microsoft released patches to address this vulnerability through regular security updates, and organizations should ensure that all Internet Explorer installations are updated to the latest security patches. Additionally, administrators can implement network-level restrictions to prevent direct access to local file system paths and consider disabling PDF printing functionality in enterprise environments where such risks are elevated. The vulnerability highlights the importance of proper metadata sanitization in document processing systems and demonstrates the need for comprehensive security testing of all browser features, particularly those involving external content processing and rendering. Organizations should also consider implementing network monitoring solutions to detect unusual patterns of local path information disclosure and establish proper access controls to limit the exposure of sensitive system information.