CVE-2015-4551 in LibreOffice
Summary
by MITRE
LibreOffice before 4.4.5 and Apache OpenOffice before 4.1.2 uses the stored LinkUpdateMode configuration information in OpenDocument Format files and templates when handling links, which might allow remote attackers to obtain sensitive information via a crafted document, which embeds data from local files into (1) Calc or (2) Writer.
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Analysis
by VulDB Data Team • 06/26/2022
The vulnerability identified as CVE-2015-4551 represents a significant information disclosure flaw affecting LibreOffice versions prior to 4.4.5 and Apache OpenOffice versions prior to 4.1.2. This security issue stems from the improper handling of link update modes within OpenDocument Format files and templates, creating a dangerous scenario where remote attackers can exploit crafted documents to access sensitive local file data. The vulnerability specifically impacts two core components of these office suites: Calc for spreadsheet processing and Writer for document creation, making it particularly concerning given the widespread use of these applications in corporate and personal environments.
The technical flaw manifests through the storage and subsequent execution of LinkUpdateMode configuration information within OpenDocument Format files. When these applications process documents containing maliciously crafted links, they inadvertently utilize stored configuration data that can trigger automatic link updates. This behavior creates an attack vector where embedded local file references can be accessed and potentially exfiltrated to remote attackers. The vulnerability operates at the document processing level, exploiting the trust model that exists between office applications and the files they process, particularly when handling external references and embedded content.
The operational impact of CVE-2015-4551 extends beyond simple information disclosure, as it represents a potential escalation path for attackers seeking to gather sensitive data from targeted systems. When users open maliciously crafted documents, the applications automatically attempt to resolve external links using stored configuration settings, potentially exposing local files, network resources, or system information that should remain protected. This vulnerability particularly affects environments where users frequently open documents from untrusted sources, including email attachments, web downloads, or shared network locations, making it a significant concern for enterprise security. The attack requires minimal user interaction beyond opening the malicious document, making it particularly dangerous in phishing scenarios.
Organizations should immediately update to LibreOffice 4.4.5 or later versions, or Apache OpenOffice 4.1.2 or later, to remediate this vulnerability. Security administrators should implement strict document filtering policies and disable automatic link updates in office applications when processing untrusted content. Additionally, users should be educated about the risks of opening documents from unknown sources and the importance of verifying document origins before opening them. This vulnerability aligns with CWE-200, which addresses information exposure, and represents a specific instance of how improper configuration handling can lead to unauthorized information disclosure. The attack pattern follows techniques outlined in the ATT&CK framework under T1059 for command and scripting interpreter and T1566 for credential access through social engineering, though the primary vector here is document-based rather than network-based.
The broader implications of this vulnerability highlight the importance of secure document processing in office applications and the need for robust input validation. This issue demonstrates how seemingly innocuous configuration settings can become security risks when not properly handled during document processing, emphasizing the critical nature of secure coding practices in application development. Organizations should also consider implementing additional security controls such as sandboxing document processing environments and monitoring for unusual file access patterns that might indicate exploitation attempts. The vulnerability serves as a reminder that office productivity applications, despite their common use, can serve as entry points for sophisticated attacks when not properly secured against malicious document content.