CVE-2017-11257 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 type confusion vulnerability in the XFA layout engine. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/31/2024
The vulnerability identified as CVE-2017-11257 represents a critical type confusion flaw within Adobe Acrobat Reader's XFA layout engine, affecting multiple versions of the software including 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier. This type confusion vulnerability occurs when the software incorrectly handles data types during processing of XFA (XML Forms Architecture) forms, creating opportunities for attackers to manipulate memory operations through malformed input files. The XFA layout engine processes complex form data structures that combine XML and scripting elements, making it a prime target for exploitation due to the intricate nature of form processing and memory management.
The technical exploitation of this vulnerability leverages the fundamental flaw in how the XFA engine manages object types during runtime operations. When processing maliciously crafted XFA forms, the engine fails to properly validate type consistency between different data structures, allowing attackers to manipulate memory pointers and execute arbitrary code with the privileges of the victim user. This type confusion scenario typically involves an attacker crafting a PDF document containing specially constructed XFA elements that cause the application to treat memory locations as different data types than intended. The vulnerability falls under CWE-466, which specifically addresses the issue of returning a pointer to data of the wrong type or category, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution.
The operational impact of this vulnerability extends beyond simple code execution to encompass full system compromise capabilities, as successful exploitation allows attackers to gain unauthorized access to victim systems. The vulnerability's exploitation requires minimal user interaction, typically involving the opening of a malicious PDF file, making it particularly dangerous in phishing campaigns and targeted attacks. Attackers can leverage this vulnerability to deploy malware, establish persistence mechanisms, or conduct further reconnaissance activities within compromised networks. The widespread adoption of Adobe Acrobat Reader across enterprise environments amplifies the potential impact, as organizations often lack robust patch management processes for desktop applications.
Mitigation strategies for CVE-2017-11257 should prioritize immediate patch deployment from Adobe, as the vendor released security updates addressing this specific vulnerability in subsequent software versions. Organizations should implement defensive measures including PDF file scanning, network-based intrusion detection systems, and user education programs to reduce the likelihood of encountering malicious documents. The vulnerability demonstrates the importance of proper input validation and type checking in complex software applications, particularly those handling untrusted data formats. Security teams should also consider implementing sandboxing mechanisms for PDF processing and establishing strict access controls for critical systems that may be exposed to untrusted document content. Additionally, regular vulnerability assessments and security audits should be conducted to identify similar type confusion vulnerabilities in other software components, as these issues often represent broader architectural weaknesses in memory management and data handling practices.