CVE-2019-7795 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2019.010.20100 and earlier, 2019.010.20099 and earlier, 2017.011.30140 and earlier, 2017.011.30138 and earlier, 2015.006.30495 and earlier, and 2015.006.30493 and earlier have an out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure.
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Analysis
by VulDB Data Team • 09/17/2023
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple versions across different release cycles. This vulnerability resides in the handling of PDF documents and occurs when the software processes malformed or specially crafted PDF files. The flaw allows an attacker to manipulate memory access patterns that exceed the allocated buffer boundaries, potentially leading to unauthorized data exposure. The vulnerability manifests during normal PDF document parsing operations when the application attempts to read data beyond the intended memory limits. This type of vulnerability falls under CWE-125, which specifically addresses out-of-bounds read conditions in software implementations. The affected versions span across several major releases including 2019.010.20100 and earlier, 2019.010.20099 and earlier, 2017.011.30140 and earlier, 2017.011.30138 and earlier, 2015.006.30495 and earlier, and 2015.006.30493 and earlier, indicating a widespread issue affecting the core PDF processing engine. The exploitation of this vulnerability can result in information disclosure, where sensitive data from the application's memory space may be accessed by an attacker. This occurs because the out-of-bounds read allows an attacker to potentially retrieve memory contents that should remain private, including but not limited to user credentials, system information, or other confidential data. The operational impact extends beyond simple information disclosure as it can serve as a stepping stone for more sophisticated attacks, potentially enabling privilege escalation or further exploitation within the target environment. Attackers typically leverage this vulnerability through social engineering campaigns where users are tricked into opening malicious PDF attachments. The attack vector aligns with ATT&CK technique T1203, which involves the use of malicious documents to gain initial access or execute code. Organizations using affected versions of Adobe Acrobat and Reader face significant security risks, as the vulnerability can be exploited remotely without requiring user interaction beyond opening the malicious document. The vulnerability represents a fundamental flaw in input validation and memory management within the PDF parsing libraries, highlighting the importance of proper bounds checking in security-critical applications. This issue underscores the necessity for regular security updates and patch management processes, as well as the implementation of network segmentation and email filtering to prevent initial compromise through malicious PDF attachments. The vulnerability's persistence across multiple release versions indicates that the underlying memory management flaw was not adequately addressed in the development lifecycle, emphasizing the need for comprehensive security testing and code review practices.
The technical exploitation of this vulnerability requires careful crafting of PDF files that trigger the specific memory access pattern causing the out-of-bounds read condition. Attackers typically construct malicious PDF documents that contain specially formatted data structures designed to cause the application to read beyond allocated buffer boundaries. The memory corruption occurs during the processing of PDF objects, particularly when handling complex data structures or malformed entries within the document's internal representation. This vulnerability can be classified as a memory safety issue that affects the application's ability to properly validate input data before processing. The information disclosure aspect of the vulnerability means that an attacker who successfully exploits this flaw could potentially extract sensitive information from the application's memory space, including potentially system-level data or user-specific information. The impact severity is elevated because the vulnerability can be exploited remotely through malicious PDF files delivered via email or web-based attacks, making it particularly dangerous in enterprise environments where users frequently open PDF documents. Organizations should note that this vulnerability affects not only the end-user applications but also the underlying PDF processing libraries that are integral to many document management systems. The vulnerability's presence in such widely used software applications creates a significant attack surface that threat actors actively exploit in targeted campaigns. Security professionals should consider implementing application whitelisting, sandboxing mechanisms, and strict email filtering policies to mitigate the risk of exploitation. The vulnerability's classification under CWE-125 emphasizes the critical importance of proper input validation and bounds checking in preventing memory safety issues. This particular flaw demonstrates how seemingly benign document processing functionality can become a significant security risk when proper safeguards are not implemented. The exploitation of this vulnerability aligns with ATT&CK technique T1059, which involves the execution of malicious code through various attack vectors including document-based attacks. Organizations should prioritize immediate patching of affected versions, as the vulnerability represents a known risk that threat actors actively monitor and exploit in real-world attacks. The widespread nature of the affected versions indicates that this vulnerability has been present for an extended period, highlighting the importance of continuous security monitoring and proactive vulnerability management strategies.