CVE-2018-4913 in Acrobat Reader
Summary
by MITRE
An issue was discovered in Adobe Acrobat Reader 2018.009.20050 and earlier versions, 2017.011.30070 and earlier versions, 2015.006.30394 and earlier versions. This vulnerability is an instance of a use after free vulnerability in the XFA engine, related to DOM manipulation. The vulnerability is triggered by crafted XFA script definitions in a PDF file. Successful exploitation could lead to arbitrary code execution.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/22/2024
The vulnerability identified as CVE-2018-4913 represents a critical use after free flaw within Adobe Acrobat Reader's XML Forms Architecture (XFA) engine, specifically manifesting during DOM (Document Object Model) manipulation operations. This security weakness affects multiple versions of Adobe Acrobat Reader including 2018.009.20050 and earlier, 2017.011.30070 and earlier, and 2015.006.30394 and earlier releases, making it a persistent threat across several product generations. The vulnerability operates through a sophisticated attack vector that leverages crafted XFA script definitions embedded within malicious PDF files, exploiting the improper memory management within the XFA processing subsystem. This particular flaw falls under the CWE-416 category, which specifically addresses use after free conditions in software development, where memory that has been freed is subsequently accessed, leading to unpredictable behavior and potential exploitation.
The technical exploitation of this vulnerability occurs when a malicious PDF file containing specially crafted XFA script definitions is opened within the affected Adobe Acrobat Reader applications. During the processing of these XFA elements, the application's memory management system fails to properly handle the lifecycle of allocated memory blocks, creating a scenario where freed memory locations become accessible again. When the XFA engine attempts to manipulate the DOM structure, it accesses this freed memory, potentially allowing an attacker to control the execution flow of the application. This memory corruption can be leveraged to execute arbitrary code within the context of the user's session, effectively providing attackers with a powerful remote code execution capability. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1203, where adversaries leverage memory corruption vulnerabilities to gain unauthorized code execution.
The operational impact of CVE-2018-4913 extends beyond simple exploitation, as it represents a significant threat to enterprise security environments where Adobe Acrobat Reader remains widely deployed. Organizations utilizing older versions of the software face substantial risk exposure, as the vulnerability can be triggered through simple document opening operations, requiring no additional user interaction beyond opening the malicious file. This makes it particularly dangerous in phishing campaigns and targeted attacks where adversaries can craft PDF documents designed to exploit this specific flaw. The vulnerability's potential for arbitrary code execution creates opportunities for attackers to establish persistent access, escalate privileges, or deploy additional malware payloads within compromised systems. Security teams must recognize that successful exploitation could result in complete system compromise, given that Adobe Acrobat Reader typically runs with elevated privileges and has extensive access to system resources.
Mitigation strategies for CVE-2018-4913 should prioritize immediate patching of affected Adobe Acrobat Reader installations to the latest available versions that contain fixes for the use after free vulnerability in the XFA engine. Organizations should implement comprehensive patch management processes to ensure all vulnerable systems are updated promptly. Additional defensive measures include deploying PDF content filtering solutions that can detect and block malicious XFA script content, implementing application whitelisting policies to restrict execution of untrusted PDF files, and conducting regular security assessments of document handling processes. Network-based intrusion detection systems should be configured to monitor for potential exploitation attempts involving crafted PDF files. The vulnerability's classification as a use after free issue underscores the importance of memory safety practices in software development and highlights the need for regular security reviews of legacy applications. Organizations should also consider implementing sandboxing techniques for PDF processing to limit the potential impact of successful exploitation attempts.