CVE-2018-4966 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 inadequate input validation within the software's memory management routines, specifically when processing malformed PDF files. The flaw manifests as a buffer overflow condition in heap memory allocation, where the application fails to properly bounds-check data before writing to allocated memory regions. Attackers can craft malicious PDF documents that trigger this vulnerability during normal document parsing operations, leading to unpredictable memory corruption patterns that adversaries can exploit for code execution.
The technical nature of this heap overflow vulnerability places it squarely within the scope of common weakness enumeration CWE-121, which categorizes heap-based buffer overflow conditions as a fundamental memory safety issue. The vulnerability operates at the intersection of software security and exploit development, where the attacker's crafted payload can manipulate heap allocation pointers and overwrite critical memory structures. This type of vulnerability is particularly dangerous because it allows for arbitrary code execution with the privileges of the currently logged-in user, bypassing many traditional security controls. The exploitation process typically involves precise memory layout manipulation and can leverage techniques such as return-oriented programming or direct code injection to achieve persistent access.
The operational impact of CVE-2018-4966 extends beyond simple privilege escalation, as successful exploitation can lead to complete system compromise through various attack vectors. The vulnerability's presence in widely deployed software versions means that organizations with legacy Adobe Reader installations face significant exposure risk. Modern exploit frameworks often target heap overflow conditions due to their reliability and the predictable memory corruption patterns they create. Security researchers have documented similar patterns in other Adobe products, indicating this may represent a broader class of vulnerabilities within the Acrobat/Reader codebase. The attack surface is particularly concerning given that PDF files are commonly shared through email attachments, web downloads, and document sharing platforms.
Mitigation strategies for this vulnerability require immediate patch management and comprehensive security monitoring. Organizations should prioritize updating to patched versions of Adobe Acrobat and Reader, specifically versions beyond the affected releases mentioned in the CVE. System administrators should implement network-based protections such as PDF sandboxing and content filtering to reduce the risk of exploitation. The vulnerability's characteristics align with tactics described in the attack mitigation framework, particularly focusing on preventing code execution in memory and monitoring for anomalous memory allocation patterns. Additional defensive measures include user education on suspicious document handling, network segmentation, and endpoint protection solutions that can detect and block malicious PDF processing activities. Regular vulnerability assessments and penetration testing should verify that all affected systems have been properly updated and that no legacy installations remain operational.