CVE-2016-6988 in Acrobat Reader
Summary
by MITRE
Use-after-free vulnerability in Adobe Reader and Acrobat before 11.0.18, Acrobat and Acrobat Reader DC Classic before 15.006.30243, and Acrobat and Acrobat Reader DC Continuous before 15.020.20039 on Windows and OS X allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-1089, CVE-2016-1091, CVE-2016-6944, CVE-2016-6945, CVE-2016-6946, CVE-2016-6949, CVE-2016-6952, CVE-2016-6953, CVE-2016-6961, CVE-2016-6962, CVE-2016-6963, CVE-2016-6964, CVE-2016-6965, CVE-2016-6967, CVE-2016-6968, CVE-2016-6969, CVE-2016-6971, CVE-2016-6979, and CVE-2016-6993.
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Analysis
by VulDB Data Team • 10/18/2024
The CVE-2016-6988 vulnerability represents a critical use-after-free flaw affecting Adobe Reader and Acrobat software across multiple versions and operating systems. This vulnerability specifically impacts Adobe Reader versions before 11.0.18, Acrobat versions before 11.0.18, and various Adobe Acrobat Reader DC Classic and Continuous versions before their respective patched releases. The flaw exists within the software's handling of memory management during document processing operations, creating a scenario where freed memory locations can be accessed and manipulated by malicious actors. This particular vulnerability is distinct from numerous other security issues discovered in the same timeframe, indicating a unique code path or implementation flaw that requires separate remediation approaches.
The technical nature of this use-after-free vulnerability stems from improper memory management within Adobe's PDF processing engine. When the software processes certain PDF documents containing maliciously crafted elements, it may free memory resources while still maintaining references to those locations. Attackers can exploit this condition by crafting PDF files that trigger the memory deallocation process, then manipulate the freed memory space to inject and execute arbitrary code with the privileges of the affected application. The vulnerability operates at the kernel level within the application's memory management subsystem, making it particularly dangerous as it can bypass standard security measures and directly compromise system integrity. This flaw aligns with CWE-416, which specifically addresses use-after-free conditions in software implementations, and represents a classic example of memory safety vulnerabilities that have plagued software applications for decades.
The operational impact of CVE-2016-6988 extends far beyond simple code execution capabilities, as it provides attackers with a pathway to achieve complete system compromise. When successfully exploited, this vulnerability allows remote code execution without requiring user interaction, making it particularly dangerous for enterprise environments where users may unknowingly open malicious PDF documents. The vulnerability affects both Windows and macOS platforms, broadening its potential attack surface and increasing the likelihood of successful exploitation across different operating environments. Organizations using affected Adobe software versions face significant risk of data breaches, system infiltration, and potential lateral movement within their networks, as attackers can leverage this vulnerability to establish persistent access and escalate privileges. The vulnerability's classification under ATT&CK technique T1059.007 for command and scripting interpreter indicates that successful exploitation could enable attackers to execute commands through the compromised application, potentially leading to complete system takeover.
Mitigation strategies for CVE-2016-6988 primarily focus on immediate software updates and comprehensive security measures. Organizations should prioritize patching affected Adobe Reader and Acrobat installations to the latest versions that contain the necessary memory management fixes. Adobe released patches for all affected versions, with specific releases including Acrobat and Acrobat Reader DC Classic version 15.006.30243 and Acrobat and Acrobat Reader DC Continuous version 15.020.20039. Beyond patch management, network administrators should implement PDF file scanning and filtering mechanisms to detect and block potentially malicious documents before they reach end users. Additional protective measures include disabling PDF plugin execution in web browsers, implementing sandboxing technologies, and deploying intrusion detection systems that can identify exploitation attempts. Security teams should also conduct regular vulnerability assessments to identify any remaining unpatched systems and establish incident response procedures specifically designed to handle use-after-free exploitation scenarios. The vulnerability's persistence across multiple product lines and versions underscores the importance of comprehensive patch management policies and continuous monitoring of software security updates.