CVE-2016-0937 in Acrobat Reader
Summary
by MITRE
Use-after-free vulnerability in the OCG object implementation in Adobe Reader and Acrobat before 11.0.14, Acrobat and Acrobat Reader DC Classic before 15.006.30119, and Acrobat and Acrobat Reader DC Continuous before 15.010.20056 on Windows and OS X allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-0932, CVE-2016-0934, CVE-2016-0940, and CVE-2016-0941.
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Analysis
by VulDB Data Team • 07/03/2022
The vulnerability described in CVE-2016-0937 represents a critical use-after-free flaw within Adobe Reader and Acrobat's Object Content Generator (OCG) implementation. This particular vulnerability affects multiple versions of Adobe's document processing software across both Windows and macOS operating systems, creating a significant attack surface for malicious actors seeking to compromise systems through document-based exploits. The OCG functionality is designed to manage optional content in PDF documents, allowing users to show or hide different elements within a document based on various conditions. However, the implementation contains a memory management error that can be exploited to execute arbitrary code on affected systems.
The technical nature of this vulnerability stems from improper memory handling within the OCG object processing code, where freed memory locations are accessed after the original allocation has been released. This use-after-free condition occurs when the application attempts to reference memory that has already been deallocated, potentially allowing attackers to manipulate the freed memory to redirect execution flow. The unspecified vectors mentioned in the description suggest that the attack could be triggered through various means including malformed PDF documents, embedded objects, or specific combinations of OCG parameters that cause the vulnerable code path to execute. This memory corruption vulnerability falls under the CWE-416 category for use-after-free conditions, which is a well-documented and frequently exploited class of vulnerabilities in software applications.
The operational impact of CVE-2016-0937 is severe and far-reaching, as it enables remote code execution attacks that can be delivered through standard PDF document attachments. Attackers can craft malicious PDF files that, when opened in vulnerable versions of Adobe Reader or Acrobat, trigger the use-after-free condition and subsequently execute malicious code with the privileges of the user running the application. This vulnerability is particularly dangerous in enterprise environments where PDF documents are frequently exchanged and opened by multiple users, as it can lead to complete system compromise, data exfiltration, and lateral movement within networks. The attack vector typically involves social engineering campaigns where users are tricked into opening malicious documents, making this vulnerability particularly effective in targeted attacks.
Organizations should prioritize immediate remediation of this vulnerability by updating to the patched versions of Adobe Reader and Acrobat as specified in the CVE details, which include versions 11.0.14, 15.006.30119, and 15.010.20056 respectively. The mitigation strategy should also incorporate additional defensive measures such as implementing PDF document scanning and filtering at network boundaries, disabling JavaScript execution in PDF readers where possible, and conducting regular security assessments of document handling processes. From an ATT&CK framework perspective, this vulnerability maps to techniques involving initial access through malicious files and privilege escalation through code execution, with potential for lateral movement once initial compromise is achieved. Security teams should also consider implementing user education programs to recognize suspicious document attachments and establish incident response procedures specifically tailored to handle PDF-based exploitation attempts.