CVE-2018-4947 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier have a Heap Overflow vulnerability. Successful exploitation could lead to arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 03/13/2023
Adobe Acrobat and Reader applications contain a critical heap overflow vulnerability that affects multiple versions across different release cycles. This vulnerability stems from improper memory management during the processing of specific PDF file structures, creating a condition where maliciously crafted input can cause the application to write beyond allocated memory boundaries. The flaw manifests when the software attempts to handle oversized or malformed data structures within PDF documents, particularly in how it processes certain embedded objects and arrays. The heap overflow occurs in the memory allocation routines that handle user-supplied data, allowing attackers to manipulate memory layout and potentially execute arbitrary code with the privileges of the currently logged-in user.
The technical exploitation of this vulnerability follows established patterns found in heap-based buffer overflow attacks and aligns with common weakness enumerations such as CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. Attackers can craft specially designed PDF files that trigger the overflow when opened by vulnerable versions of Adobe Acrobat or Reader. The exploitation process typically involves careful manipulation of memory layout through controlled input data that causes the heap allocator to write beyond intended boundaries, potentially allowing code execution through return-oriented programming techniques or direct memory corruption. This vulnerability directly maps to attack techniques documented in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data exfiltration capabilities. When successfully exploited, the vulnerability allows attackers to execute malicious code within the context of the user's session, potentially leading to full system compromise if the user has administrative privileges. The affected versions span several years of Adobe's product lifecycle, indicating a prolonged window of exposure that makes this vulnerability particularly concerning for enterprise environments where legacy software may persist. Organizations running these vulnerable versions face significant risk as the exploit can be delivered through standard phishing campaigns or malicious document attachments, requiring minimal user interaction beyond opening the compromised PDF file.
Mitigation strategies for this vulnerability require immediate patching of affected Adobe Acrobat and Reader installations to the latest versions that contain memory safety improvements and heap management fixes. System administrators should implement comprehensive software update policies that ensure all endpoints are running patched versions of Adobe products, particularly in environments where users may encounter untrusted PDF documents. Additional defensive measures include implementing PDF sandboxing capabilities where available, restricting user privileges when opening documents, and deploying email filtering solutions that can detect and quarantine potentially malicious PDF attachments. Network-based protections such as web application firewalls and content inspection systems can also provide additional layers of defense by analyzing PDF content for known malicious patterns or structures that may trigger the heap overflow condition. Organizations should also consider implementing user education programs to raise awareness about the risks of opening untrusted PDF documents and the importance of keeping software updated.