CVE-2016-6963 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-2016-6964, CVE-2016-6965, CVE-2016-6967, CVE-2016-6968, CVE-2016-6969, CVE-2016-6971, CVE-2016-6979, CVE-2016-6988, and CVE-2016-6993.
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Analysis
by VulDB Data Team • 10/17/2024
This vulnerability represents a critical use-after-free condition affecting Adobe Reader and Acrobat products across multiple versions, specifically targeting Windows and macOS operating systems. The flaw occurs when the application improperly handles memory management during processing of certain file formats, creating opportunities for attackers to manipulate freed memory locations. The vulnerability is classified under CWE-416 as a use-after-free error, which represents a well-known class of memory corruption vulnerabilities that have historically enabled remote code execution attacks. Unlike other CVEs in the same advisory, this particular issue involves distinct exploitation vectors that distinguish it from the related vulnerabilities such as CVE-2016-1089 and CVE-2016-1091, indicating separate code paths within the affected software components. The vulnerability affects both the legacy Acrobat and Reader DC Classic versions as well as the continuous delivery model, demonstrating the widespread nature of the memory management flaw across Adobe's product lineage. Attackers can leverage this weakness by crafting malicious documents that trigger the vulnerable code path, causing the application to access memory that has already been freed and potentially overwritten by other operations.
The operational impact of this vulnerability extends beyond simple exploitation as it provides attackers with a pathway to achieve arbitrary code execution within the context of the Adobe application process. This privilege escalation capability allows adversaries to bypass typical security controls and potentially establish persistent access to compromised systems. The vulnerability's presence in both classic and continuous delivery versions of Adobe's products creates a broad attack surface, particularly affecting enterprise environments where these applications are commonly deployed. Security researchers have noted that use-after-free vulnerabilities of this nature often require specific conditions to be met for successful exploitation, including proper memory layout control and exploitation techniques such as heap spraying or controlled memory corruption. The vulnerability's classification aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would likely involve executing malicious payloads through the compromised application. The affected versions span a significant timeframe, indicating that Adobe had not fully addressed the underlying memory management issues across their product versions, leaving users vulnerable for extended periods.
Mitigation strategies for this vulnerability should encompass multiple layers of defense to protect against exploitation attempts. Organizations should prioritize immediate patching of affected Adobe products to the latest available versions, specifically targeting the fixed releases mentioned in Adobe's security advisories for both classic and continuous delivery models. System administrators should implement application whitelisting policies that restrict execution of untrusted PDF documents and consider deploying sandboxing solutions to isolate Adobe Reader processes from critical system resources. Network-based protections including web application firewalls and content filtering systems can help prevent the delivery of malicious PDF files to user systems. Security teams should also monitor for indicators of compromise related to exploitation attempts, particularly focusing on unusual network connections or file access patterns that might indicate successful exploitation. The vulnerability's nature makes it particularly susceptible to exploitation through social engineering campaigns targeting users to open malicious PDF attachments, making user awareness training and email filtering solutions essential components of the overall defense strategy. Adobe's security advisory recommends that users disable JavaScript in PDF documents when possible, as JavaScript execution often provides additional attack vectors that could compound the impact of this vulnerability. Regular security assessments should include verification that the patched versions are properly deployed and that no legacy installations remain that could be vulnerable to this and similar memory corruption issues.