CVE-2019-7773 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 • 06/14/2024
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 malformed PDF files and occurs when the software attempts to read memory locations beyond the allocated buffer boundaries. The flaw manifests during the processing of specially crafted PDF documents that contain malformed data structures, particularly in the way the applications parse and interpret certain object types within the document hierarchy. The out-of-bounds read condition allows an attacker to access memory regions that should not be accessible, potentially exposing sensitive data from the application's memory space.
The technical implementation of this vulnerability falls under CWE-129, which represents "Improper Validation of Array Index" and is categorized as a memory safety issue within the broader context of software security weaknesses. When the vulnerable Adobe applications process malicious PDF files, they fail to properly validate the bounds of array indices used during PDF object parsing, leading to unauthorized memory access patterns. This particular flaw is classified as a remote code execution vulnerability because attackers can craft malicious PDF documents that trigger the out-of-bounds read condition when opened by vulnerable versions of Adobe Acrobat or Reader. The exploitation mechanism relies on the attacker controlling the input data stream that the application processes, specifically targeting memory access patterns that result in information disclosure rather than direct code execution.
From an operational perspective, this vulnerability poses significant risks to enterprise environments where Adobe Acrobat and Reader are widely deployed across multiple platforms and user groups. The impact extends beyond simple information disclosure, as the leaked memory contents could contain sensitive information such as encryption keys, user credentials, or internal application state data that could be leveraged in subsequent attacks. The vulnerability's remote nature means that attackers can deliver malicious payloads through email attachments, web downloads, or compromised websites without requiring any special privileges or local access to the target system. Organizations running affected versions of Adobe software face potential data breaches and unauthorized access to sensitive documents and information stored within the application's memory space. The vulnerability affects both desktop and mobile deployments, making it particularly dangerous in environments where users frequently access PDF documents from untrusted sources.
The exploitation of CVE-2019-7773 aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to initial access and privilege escalation. Attackers can leverage this vulnerability as part of a broader attack chain, using the information disclosure capability to gather intelligence about the target environment before moving to more sophisticated attack vectors. The vulnerability's presence in multiple release versions of Adobe software means that organizations must carefully assess their deployment environments and ensure all systems are updated to the latest patched versions. Security teams should implement network monitoring to detect suspicious PDF file access patterns and consider deploying sandboxing solutions to isolate PDF processing activities. Additionally, user education programs should emphasize the importance of only opening PDF files from trusted sources and avoiding potentially malicious attachments or downloads. The remediation process requires immediate patch deployment across all affected systems, with particular attention to ensuring that updates are properly applied and validated across different operating system platforms where Adobe products are installed.