CVE-2015-6688 in Acrobat Reader
Summary
by MITRE
Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.16 and 11.x before 11.0.13, Acrobat and Acrobat Reader DC Classic before 2015.006.30094, and Acrobat and Acrobat Reader DC Continuous before 2015.009.20069 on Windows and OS X allows attackers to execute arbitrary code via a crafted Optional Content Groups (OCG) object in a WillSave document action, a different vulnerability than CVE-2015-5586, CVE-2015-6683, CVE-2015-6684, CVE-2015-6687, CVE-2015-6689, CVE-2015-6690, CVE-2015-6691, CVE-2015-7615, CVE-2015-7617, and CVE-2015-7621.
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Analysis
by VulDB Data Team • 06/21/2022
This vulnerability represents a critical use-after-free flaw in Adobe Reader and Acrobat products that enables remote code execution through maliciously crafted document content. The vulnerability specifically affects versions prior to 10.1.16 and 11.0.13 for traditional Acrobat versions, as well as older releases of the DC Classic and DC Continuous variants. The flaw manifests when processing Optional Content Groups (OCG) objects within WillSave document actions, creating a scenario where freed memory locations are accessed after being deallocated, leading to potential arbitrary code execution capabilities.
The technical implementation of this vulnerability involves the improper handling of memory management during document processing operations. When Adobe Reader encounters a crafted OCG object within a WillSave document action, the application fails to properly validate or manage the memory associated with these objects, resulting in a situation where memory that has been freed is subsequently accessed. This memory corruption allows attackers to manipulate the execution flow of the application and potentially inject malicious code. The vulnerability is classified under CWE-416 as a Use After Free condition, which occurs when a program continues to reference memory after it has been freed, creating a potential exploitation vector for privilege escalation attacks.
The operational impact of this vulnerability extends across multiple platforms including Windows and OS X operating systems, making it particularly dangerous for enterprise environments where these applications are commonly deployed. Attackers can exploit this vulnerability by crafting malicious PDF documents that contain specially formatted OCG objects designed to trigger the memory corruption during document processing. The attack requires no user interaction beyond opening the malicious document, making it particularly effective for phishing campaigns and targeted attacks. This vulnerability is distinct from several other related CVEs in the same year, indicating a unique exploitation path that requires specific conditions to be met for successful exploitation.
Security professionals should note that this vulnerability represents a significant risk to organizations relying on Adobe Reader and Acrobat for document processing. The use-after-free condition creates a predictable exploitation pattern that can be leveraged for privilege escalation attacks, potentially allowing attackers to execute code with the privileges of the affected user. Mitigation strategies should include immediate patching of affected versions, implementing application whitelisting policies, and deploying network-based protections to detect and block malicious PDF content. Organizations should also consider restricting user permissions when processing documents and implementing sandboxing techniques to limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the importance of proper memory management in document processing applications and highlights the need for continuous security testing and vulnerability assessment of widely deployed software components.