CVE-2018-4968 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 version ranges including 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier. This vulnerability resides in the handling of specific PDF file structures and occurs when the software processes malformed or specially crafted PDF content that triggers improper memory management during heap allocation operations. The heap overflow represents a fundamental memory corruption flaw that falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based and heap-based buffer overflow conditions that can lead to arbitrary code execution. The vulnerability manifests when the application attempts to write data beyond the allocated heap memory boundaries, creating a condition where attacker-controlled input can overwrite adjacent memory locations and potentially redirect program execution flow.
The operational impact of this vulnerability extends beyond simple memory corruption as it provides a pathway for remote code execution attacks that can be leveraged by malicious actors. When an unsuspecting user opens a specially crafted PDF file, the heap overflow condition can be triggered, allowing attackers to execute arbitrary code with the privileges of the current user account. This represents a significant escalation from a local privilege escalation vulnerability to a full remote code execution vector that can be exploited through social engineering or automated attack vectors. The vulnerability is particularly dangerous because it operates within the context of the user who opens the malicious document, meaning that successful exploitation could lead to complete system compromise without requiring additional attack vectors or privilege escalation techniques.
Security researchers have identified this vulnerability as part of the broader ATT&CK framework's technique T1059, which encompasses the execution of malicious code through various attack vectors including document-based exploits. The heap overflow in Adobe Reader and Acrobat implementations demonstrates how memory safety issues in widely used applications can create persistent security risks that affect millions of users globally. Organizations running affected versions of Adobe software face significant exposure as the vulnerability can be exploited through email attachments, web downloads, or other delivery mechanisms that trick users into opening malicious PDF files. The vulnerability's exploitation potential aligns with ATT&CK technique T1203, which covers the use of malicious files for initial access and privilege escalation, making it a critical concern for enterprise security teams managing document processing workflows and user access controls.
The recommended mitigation strategy involves immediate patching of all affected Adobe Acrobat and Reader installations to the latest versions that contain memory safety fixes and heap management improvements. Organizations should also implement comprehensive security controls including email filtering, web content filtering, and user education to reduce the likelihood of users encountering malicious PDF files. Network segmentation and application whitelisting can provide additional defense-in-depth measures to limit the potential impact of successful exploitation attempts. The vulnerability's classification under CWE-121 and its exploitation patterns align with industry best practices for memory safety and secure coding standards that emphasize proper bounds checking, memory allocation validation, and robust error handling in software applications processing untrusted input data.