CVE-2018-4909 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 as a result of computation that reads data that is past the end of the target buffer; the computation is part of the image conversion module when processing metadata in JPEG images. A successful attack can lead to sensitive data exposure.
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Analysis
by VulDB Data Team • 02/10/2023
This vulnerability in Adobe Acrobat Reader represents a classic buffer overflow condition that arises during image processing operations within the application's metadata handling subsystem. The flaw manifests specifically when the software processes JPEG images containing specially crafted metadata that triggers an out-of-bounds memory read operation. The vulnerability exists in multiple versions of the Acrobat Reader application spanning different release cycles, indicating a persistent issue within the image conversion module that has remained unaddressed across several major releases. The affected components are part of the core image processing pipeline where the application attempts to parse and convert metadata from JPEG files, creating a scenario where computational logic fails to properly validate buffer boundaries during data extraction.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software systems. When processing JPEG metadata, the application's image conversion module performs calculations that determine memory offsets for data extraction without adequate boundary checks. This allows an attacker to craft malicious JPEG files that, when opened in the vulnerable versions of Acrobat Reader, cause the application to read memory locations beyond the intended buffer boundaries. The computational error occurs during the metadata parsing phase where the software assumes certain data structures maintain expected sizes and layouts, failing to account for malformed or oversized metadata fields that could extend beyond allocated memory regions.
From an operational perspective, this vulnerability presents a significant risk to end users who may encounter maliciously crafted PDF documents containing compromised JPEG images. The attack vector requires the user to open a specially constructed PDF file that contains JPEG images with malicious metadata, making this a client-side exploitation scenario. Successful exploitation can result in sensitive data exposure as the out-of-bounds read may retrieve information from adjacent memory locations that could contain passwords, session tokens, or other confidential information. The vulnerability does not require user interaction beyond opening the document, making it particularly dangerous for targeted attacks where adversaries can deliver malicious payloads through email attachments or web downloads.
The attack surface for this vulnerability extends beyond simple data exposure to potential privilege escalation and system compromise. According to ATT&CK framework techniques, this represents a code execution vector through application sandbox escape scenarios where an attacker can leverage the memory corruption to gain unauthorized access to system resources. The vulnerability's persistence across multiple release versions suggests that it may be part of a fundamental architectural flaw in the image processing library used by Adobe Reader, making it challenging to remediate without complete code rewrites. Organizations should prioritize patch management for this vulnerability as it represents a critical security gap that can be exploited without requiring user interaction beyond document opening.
Mitigation strategies should include immediate deployment of Adobe's security patches for all affected versions of Acrobat Reader, as well as implementing network-based controls to filter potentially malicious PDF files before they reach end users. Organizations should also consider implementing application whitelisting policies that restrict execution of Acrobat Reader to trusted environments and deploy endpoint protection solutions that can detect and block suspicious file processing activities. The vulnerability highlights the importance of robust input validation in multimedia processing components and underscores the need for regular security assessments of third-party libraries used in enterprise applications. Security teams should monitor for indicators of compromise related to this vulnerability and implement logging mechanisms to detect unauthorized access attempts through malicious document processing activities.