CVE-2016-6952 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-2016-6953, 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, CVE-2016-6988, and CVE-2016-6993.
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Analysis
by VulDB Data Team • 09/23/2022
This use-after-free vulnerability exists in Adobe Reader and Acrobat products across multiple versions, specifically affecting Windows and macOS operating systems. The flaw occurs when the application processes certain maliciously crafted PDF files, leading to memory management issues that can be exploited by attackers. The vulnerability is classified as a classic use-after-free condition where a program continues to reference memory that has already been freed, creating opportunities for arbitrary code execution. This particular vulnerability differs from several other CVEs in the same year, indicating it represents a distinct code path or memory handling scenario within Adobe's PDF processing engine. The vulnerability affects both the traditional Acrobat and Reader versions as well as the newer DC Classic and Continuous editions, suggesting it stems from fundamental memory management issues in the core PDF rendering components.
The technical exploitation of this vulnerability involves crafting malicious PDF content that triggers the specific memory access pattern leading to the use-after-free condition. When a user opens the malicious document, the application's handling of certain PDF objects causes memory to be freed while still being referenced elsewhere in the code execution path. This creates a situation where an attacker can manipulate the freed memory to redirect execution flow or inject malicious code. The vulnerability is particularly dangerous because it can be triggered through normal document opening behavior, requiring no special privileges or user interaction beyond viewing the compromised file. Attackers can leverage this condition to execute arbitrary code with the privileges of the affected application, potentially leading to complete system compromise. The memory corruption can be exploited through various code injection techniques, including return-oriented programming or direct code execution within the application's memory space.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities. When successfully exploited, the vulnerability allows attackers to execute malicious code in the context of the Adobe Reader or Acrobat process, which typically runs with elevated privileges on modern operating systems. This can result in unauthorized access to sensitive data, system file modification, or complete system takeover. The vulnerability affects users across multiple platforms, making it particularly concerning for enterprise environments where Adobe Reader is widely deployed. Organizations may face significant security risks as users routinely open PDF documents from various sources, including email attachments, web downloads, and shared network drives. The vulnerability's presence in both traditional and newer DC versions indicates that the underlying memory management issues persist across different product generations, requiring comprehensive patching strategies across all affected installations.
Mitigation strategies for this vulnerability require immediate patching of all affected Adobe Reader and Acrobat installations across the enterprise environment. Organizations should prioritize updating to the latest versions that address this specific memory management issue, ensuring that both the traditional and DC versions are properly patched. Network administrators should implement content filtering measures to block suspicious PDF files and monitor for potential exploitation attempts. Security teams should also consider implementing application whitelisting policies to restrict execution of untrusted PDF content and deploy sandboxing solutions to isolate PDF processing activities. The vulnerability's classification under CWE-416 indicates it falls within the category of improper deallocation issues, making it particularly susceptible to exploitation through memory corruption techniques. Organizations should also monitor for indicators of compromise related to this vulnerability, including unusual network connections or file modifications that may indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to ensure all systems remain protected against this and similar memory corruption vulnerabilities.