CVE-2017-11223 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier has an exploitable use after free vulnerability in the core of the XFA engine. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/30/2024
The vulnerability identified as CVE-2017-11223 represents a critical use after free flaw within Adobe Acrobat Reader's XFA (XML Forms Architecture) engine, affecting multiple versions including 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier. This vulnerability resides in the core processing components of the XFA engine which handles XML-based form data within PDF documents, making it particularly dangerous as it can be triggered through routine PDF document processing activities. The flaw occurs when the application fails to properly manage memory allocation and deallocation, creating conditions where freed memory locations can be accessed and reused, leading to unpredictable behavior.
The technical exploitation of this vulnerability leverages the improper handling of memory objects within the XFA processing pipeline, specifically when parsing malformed XML content embedded within PDF documents. When a maliciously crafted PDF file is opened, the XFA engine processes the document structure and encounters corrupted or malformed XML elements that trigger the use after free condition. This memory management error allows attackers to manipulate the application's memory state, potentially enabling arbitrary code execution with the privileges of the user running the vulnerable software. The vulnerability directly maps to CWE-416, which defines use after free conditions as a critical memory safety issue, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage in exploitation scenarios.
The operational impact of this vulnerability extends far beyond typical security concerns, as Adobe Acrobat Reader is widely deployed across enterprise environments and individual workstations for document viewing and form processing. Attackers can leverage this vulnerability through spearphishing campaigns, malicious document delivery, or supply chain attacks targeting organizations that rely heavily on PDF document processing. Successful exploitation can result in complete system compromise, data exfiltration, and persistence mechanisms being established within the victim environment. The vulnerability's exploitability is heightened by the fact that it requires no user interaction beyond opening a malicious document, making it particularly dangerous for targeted attacks. Organizations using older versions of Acrobat Reader face significant risk exposure, as these versions lack the memory safety improvements and security mitigations present in updated releases. The vulnerability's classification as critical by major security vendors underscores its potential for widespread exploitation and the urgent need for immediate remediation across affected systems.
Mitigation strategies should prioritize immediate patching of all affected Adobe Acrobat Reader versions to the latest security updates provided by Adobe. Organizations should implement network-based security controls including PDF file content filtering and sandboxing mechanisms to prevent execution of potentially malicious documents. Additional defensive measures include restricting user permissions when processing PDF documents, implementing email security filtering to block suspicious attachments, and conducting regular security awareness training to reduce successful social engineering attacks. The use of endpoint detection and response solutions can help identify exploitation attempts through anomalous memory access patterns or process behavior. System administrators should also consider deploying application whitelisting policies to restrict execution of unauthorized software and reduce the attack surface. Regular vulnerability assessments and penetration testing should be conducted to ensure comprehensive coverage of all potential attack vectors related to document processing applications.