CVE-2018-4883 in Acrobat Reader
Summary
by MITRE
An issue was discovered in Adobe Acrobat Reader 2018.009.20050 and earlier versions, 2017.011.30070 and earlier versions, 2015.006.30394 and earlier versions. This vulnerability occurs because of computation that reads data that is past the end of the target buffer; the computation is part of the image conversion engine that handles Enhanced Metafile Format (EMF). A successful attack can lead to sensitive data exposure.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/23/2024
This vulnerability in Adobe Acrobat Reader represents a classic buffer overflow condition that occurs within the image conversion engine responsible for processing Enhanced Metafile Format files. The flaw manifests when the software attempts to read data beyond the boundaries of a targeted buffer during EMF image processing operations. This type of vulnerability falls under the CWE-125 category of "Out-of-bounds Read" which is a fundamental memory safety issue that has been a persistent concern in software development for decades. The vulnerability affects multiple versions of Adobe Acrobat Reader spanning from 2015 through 2018, indicating a prolonged exposure period that allowed potential attackers to exploit the weakness across various deployment environments.
The technical implementation of this vulnerability involves the image conversion engine's handling of EMF files where computational operations fail to properly validate buffer boundaries before reading data. When processing maliciously crafted EMF files, the software performs calculations that assume certain data structures exist within predetermined memory boundaries, but these assumptions prove incorrect when encountering malformed input. The out-of-bounds read behavior specifically targets the memory management aspects of the conversion engine, allowing attackers to potentially access adjacent memory regions that may contain sensitive information such as encryption keys, user credentials, or other confidential data. This vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" in that it enables attackers to extract sensitive data through memory corruption techniques.
The operational impact of this vulnerability extends beyond simple data exposure, as it represents a potential pathway for more sophisticated attacks within the broader threat landscape. An attacker who successfully exploits this vulnerability could gain access to sensitive data that might be stored in adjacent memory locations, potentially compromising the integrity of the application's memory space. The vulnerability's presence in widely deployed versions of Adobe Acrobat Reader means that organizations using these applications face significant risk, particularly in environments where PDF documents are frequently exchanged. The attack vector through EMF files demonstrates how legacy file format processing can introduce security weaknesses, especially when dealing with complex graphics formats that require extensive parsing operations. This vulnerability also highlights the importance of proper input validation and memory boundary checking in multimedia processing components, which are often overlooked in security assessments.
Mitigation strategies for this vulnerability require immediate patch application from Adobe, as the company released security updates specifically addressing this issue in their software releases. Organizations should implement comprehensive patch management procedures to ensure timely deployment of security fixes across all affected systems. Additionally, network administrators should consider implementing sandboxing measures for PDF processing, particularly when dealing with untrusted documents from external sources. The vulnerability's classification as a buffer overflow makes it susceptible to exploitation through carefully crafted EMF files that could be embedded in PDF documents, making content filtering and email security measures essential. Security teams should also consider implementing monitoring for unusual PDF processing activities and memory access patterns that might indicate exploitation attempts. Regular security assessments of document processing components and adherence to secure coding practices, particularly regarding buffer management and input validation, should be prioritized to prevent similar vulnerabilities from emerging in the future.